                 Linux Frequently Asked Questions with Answers
                                       

   October 4, 1998
   
   This is the list of Frequently Asked Questions for Linux, the free
   Unix for just about every computer hardware platform on the planet.
   Originally written for 386/486/586 Intel/ISA bus machines, versions
   exist for Alpha, MIPS, ARM, 680x0, and PPC processors, and many
   others. (See the question, "What is Linux? " below.) This
   document should be read in conjunction with the Linux Documentation
   Project's HOWTO series. ("Where can I get Linux material by FTP?
   " and, "Where can I get the HOWTO's and other documentation? ")
   The INFO-SHEET and META-FAQ, which are found in the same place, als
   list sources of Linux information. Please look at these documents,
   and, "You still haven't answered my question! " before posting
   to a Usenet news group. You can also get Postscript, HTML, SGML, an
   plain ASCII versions of this document. ("Formats in which this
   FAQ is available. ")
   
1. Introduction and General Information 

     * 1.1 What is Linux? 
     * 1.2 Where do I start? 
     * 1.3 What software does Linux support? 
     * 1.4 Does Linux run on my computer? What hardware is supported?
     * 1.5 What ports to other processors are there? 
     * 1.6 How much hard disk space does Linux need? 
     * 1.7 How much memory does Linux need? 
     * 1.8 How much memory can Linux use? 
     * 1.9 Is Linux public domain? Copyrighted? 
       
2. Network sources and resources. 

     * 2.1 Where can I get the HOWTO's and other documentation? 
     * 2.2 Where should I look on the World Wide Web for Linux stuff?
     * 2.3 What newsgroups are there for Linux? 
     * 2.4 Where can I find out about Linux and the Millennium (Y2K)
       bug? 
     * 2.5 Where can I get Linux material by FTP? 
     * 2.6 I don't have FTP access. Where do I get Linux? 
     * 2.7 I don't have Usenet access. Where do I get information? 
     * 2.8 What mailing lists are there? 
     * 2.9 Are the newsgroups archived anywhere? 
       
3. Compatibility with other operating systems. 

     * 3.1 Can Linux share my disk with DOS? OS/2? 386BSD? Win95? 
     * 3.2 How do I access files on my DOS partition or floppy? 
     * 3.3 Does Linux support compressed ext2 file systems? 
     * 3.4 Can I use my Stacked/DBLSPC/etc. DOS drive? 
     * 3.5 Can I access OS/2 HPFS partitions from Linux? 
     * 3.6 Can Linux access Amiga file systems? 
     * 3.7 Can Linux access BSD, SysV, etc. UFS? 
     * 3.8 Can Linux access SMB file systems? 
     * 3.9 Can Linux access Macintosh file systems? 
     * 3.10 Can I run Microsoft Windows programs under Linux? 
     * 3.11 How can I boot Linux from OS/2's Boot Manager? 
     * 3.12 How can I share a swap partition between Linux and MS
       Windows? 
       
4. Linux's handling of file systems, disks, and drives 

     * 4.1 How can I get Linux to work with my disk? 
     * 4.2 How can I undelete files? 
     * 4.3 Is there a defragmenter for ext2fs etc.? 
     * 4.4 How do I format and create a file system on a floppy? 
     * 4.5 I get nasty messages about inodes, blocks, and the like. 
     * 4.6 My swap area isn't working. 
     * 4.7 How do I remove LILO so my system boots DOS again? 
     * 4.8 Why can't I use fdformat except as root? 
     * 4.9 My ext2fs partitions are checked each time I reboot. 
     * 4.10 My root file system is read-only! 
     * 4.11 I have a huge /proc/kcore! Can I delete it? 
     * 4.12 My AHA1542C doesn't work with Linux. 
       
5. Porting, compiling and obtaining programs 

     * 5.1 How do I compile programs? 
     * 5.2 How do I port XXX to Linux? 
     * 5.3 What is ld.so and where do I get it? 
     * 5.4 How do I upgrade the libraries withough trashing my
       system? 
     * 5.5 Has anyone ported / compiled / written XXX for Linux? 
     * 5.6 Can I use code or a compiler compiled for a 486 on my 386?
     * 5.7 What does gcc -O6 do? 
     * 5.8 Where are linux/*.h and asm/*.h? 
     * 5.9 I get errors when I try to compile the kernel. 
     * 5.10 How do I make a shared library? 
     * 5.11 My executables are (very) large. 
     * 5.12 Does Linux support threads or lightweight processes? 
     * 5.13 Where can I get `lint' for Linux? 
     * 5.14 Where can I find kermit for Linux? 
       
6. Solutions to common miscellaneous problems. 

     * 6.1 free dumps core. 
     * 6.2 My clock is very wrong. 
     * 6.3 Setuid scripts don't seem to work. 
     * 6.4 Free memory as reported by free keeps shrinking. 
     * 6.5 When I add more memory, the system slows to a crawl. 
     * 6.6 Some programs (e.g. xdm) won't let me log in. 
     * 6.7 Some programs let me log in with no password. 
     * 6.8 My machine runs very slowly when I run GCC / X / ... 
     * 6.9 I can only log in as root. 
     * 6.10 My screen is all full of weird characters instead of
       letters. 
     * 6.11 I have screwed up my system and can't log in to fix it. 
     * 6.12 I've discovered a huge security hole in rm! 
     * 6.13 lpr(1) and/or lpd(8) don't work. 
     * 6.14 Timestamps on files on MS-DOS partitions are set
       incorrectly. 
     * 6.15 How do I get LILO to boot the vmlinux file? 
       
7. How do I do this or find out that ... ? 

     * 7.1 How can I get scrollback in text mode? 
     * 7.2 How do I switch virtual consoles? How do I enable them? 
     * 7.3 How do I set the time zone? 
     * 7.4 What version of Linux and what machine name am I using? 
     * 7.5 How can I enable or disable core dumps? 
     * 7.6 How do I upgrade/recompile my kernel? 
     * 7.7 Can I have more than 3 serial ports by sharing interrupts?
     * 7.8 How do I make a bootable floppy? 
     * 7.9 How do I remap my keyboard to UK, French, etc.? 
     * 7.10 How do I get NUM LOCK to default to on? 
     * 7.11 How do I set (or reset) my initial terminal colors?
     * 7.12 How can I have more than 128Mb of swap? 
       
8. Miscellaneous information and questions answered. 

     * 8.1 How do I program XYZ under Linux? 
     * 8.2 What's all this about ELF? 
     * 8.3 What is a .gz file ? And a .tgz ? And ... ? 
     * 8.4 What does VFS stand for? 
     * 8.5 What is a BogoMip? 
     * 8.6 What is the Linux Journal and where can I get it? 
     * 8.7 What online/free periodicals exist for Linux? 
     * 8.8 How many people use Linux? 
     * 8.9 How should I pronounce Linux? 
       
9. Frequently encountered error messages. 

     * 9.1 Modprobe can't locate module, "XXX," and similar
       messages. 
     * 9.2 Unknown terminal type linux and similar. 
     * 9.3 lp1 on fire 
     * 9.4 INET: Warning: old style ioctl... called! 
     * 9.5 ld: unrecognized option '-m486' 
     * 9.6 GCC says Internal compiler error. 
     * 9.7 make says Error 139 
     * 9.8 shell-init: permission denied when I log in. 
     * 9.9 No utmp entry. You must exec ... when I log in. 
     * 9.10 Warning--bdflush not running. 
     * 9.11 Warning: obsolete routing request made. 
     * 9.12 EXT2-fs: warning: mounting unchecked file system. 
     * 9.13 EXT2-fs warning: maximal count reached. 
     * 9.14 EXT2-fs warning: checktime reached. 
     * 9.15 df says Cannot read table of mounted file systems. 
     * 9.16 fdisk says Partition X has different physical/logical
       ... 
     * 9.17 fdisk: Partition 1 does not start on cylinder boundary. 
     * 9.18 fdisk says partition n has an odd number of sectors. 
     * 9.19 mtools says cannot initialize drive XYZ 
     * 9.20 At the start of booting: Memory tight 
     * 9.21 My syslog says `end_request: I/O error, ...'. 
     * 9.22 You don't exist. Go away. 
       
10. The X Window System. 

     * 10.1 Does Linux support X Windows? 
     * 10.2 Where can I get an XF86Config for my system? 
     * 10.3 xterm logins show up strangely in who, finger. 
     * 10.4 I can't get X Windows to work right. 
       
11. Questions applicable to very out-of-date software. 

     * 11.1 fdisk says cannot use nnn sectors of this partition. 
     * 11.2 GCC sometimes uses huge amounts of virtual memory and
       thrashes.
       
12. How to get further assistance. 

     * 12.1 You still haven't answered my question! 
     * 12.2 What to put in a request for help. 
     * 12.3 I want to mail someone about my problem. 
       
13. Administrative information and acknowledgments. 

     * 13.1 Feedback is invited. 
     * 13.2 Formats in which this FAQ is available. 
     * 13.3 Authorship and acknowledgments. 
     * 13.4 Disclaimer and Copyright. 
   
   
   
1. Introduction and General Information

1.1 What is Linux?

   Linux is the free Unix written from scratch by Linus Torvalds with
   assistance from a loosely-knit team of hackers from across the
   Internet. Linux aims towards POSIX compliance, and has all of the
   features you would expect of a modern, fully fledged Unix: true
   multitasking, virtual memory, shared libraries, demand loading,
   shared, copy-on-write executables, proper memory management, and
   TCP/IP networking.
   
   Linux runs mainly on 386/486/586-based PC's, using the hardware
   facilities of the 80386 processor family (TSS segments, et al.) to
   implement these features. Ports to other architectures are underway
   (See, "What ports to other processors are there? ")
   
   See the Linux INFO-SHEET for more details. ("Where can I get
   the HOWTO's and other documentation? ")
   
   The Linux kernel is distributed under the GNU General Public Licens
   ("Is Linux public domain? Copyrighted? ")
   
   
1.2 Where do I start?

   There are a handful of major Linux distributions. For information
   about them, and how they are installed, see Matthew Welsh's
   Installation and Getting Started, or IGS for short. It's located at
   the Linux Documentation Project Home Page,
   http://sunsite.unc.edu/LDP.
   
   There is also an Installation HOWTO on the LDP Home Page.
   
   Most of the distributions are available via anonymous FTP from vari
   Linux archive sites. ("Where can I get Linux material by FTP?
   ") There are also a large number of other releases which are
   distributed less globally that suit special local and national need
   
   
1.3 What software does Linux support?

   Linux supports GCC, Emacs, the X Window System, all the standard Un
   utilities, TCP/IP (including SLIP and PPP), and all of the hundreds
   programs that people have compiled or ported to it.
   
   There is a DOS emulator, called DOSEMU. The latest stable release i
   0.98.1. The FTP archives are at ftp://ftp.dosemu.org/dosemu. The
   Web site is htmlurl url="http://www.dosemu.org"
   name="http://www.dosemu.org">.
   
   The emulator can run DOS itself and some (but not all) DOS
   applications. Be sure to look at the README file to determine which
   version you should get. Also, see the DOSEMU-HOWTO (slightly dated 
   this point--it doesn't cover the most recent version of the program
   at sunsite.unc.edu/pub/Linux/docs/HOWTO.
   
   Work has been progressing on an emulator for Microsoft Windows
   binaries. ("Can I run Microsoft Windows programs under Linux?
   ")
   
   iBCS2 (Intel Binary Compatibility Standard) emulator code for SVR4 
   and SVR3.2 COFF binaries can be included in the kernel as a
   compile-time option. There is information at
   tsx-11.mit.edu/pub/linux/BETA/ibcs2/README.
   
   For more information see the INFO-SHEET, which is one of the HOWTO'
   ("Where can I get the HOWTO's and other documentation? " and,
   "How do I port XXX to Linux? ")
   
   Some companies have commercial software available, including Motif.
   They announce their availability in comp.os.linux.announce--try
   searching the archives. ("Are the newsgroups archived anywhere?
   ")
   
   
1.4 Does Linux run on my computer? What hardware is supported?

   Giving Linux a try requires a machine with an Intel '386, '486, or
   '586 processor with at least 2Mb of RAM and a single floppy drive. 
   do anything useful, more RAM and disk space is needed. ("How
   much memory does Linux need? ")
   
   VESA Local Bus and PCI are supported.
   
   MCA (IBM's proprietary bus) and ESDI hard drives are mostly support
   There is further information on the MCA bus and what cards Linux
   supports on the Micro Channel Linux Web page,
   http://glycerine.itsmm.uni.edu/mca.
   
   Linux runs on '386 family based laptops, with X on most of them. Th
   is a Web page at
   http://www.cs.utexas.edu/users/kharker/linux-laptop/.
   
   For details of exactly which PC's, video cards, disk controllers, e
   work see the INFO-SHEET and the Hardware-HOWTO. (See "Where can
   I get the HOWTO's and other documentation? ")
   
   There is a port of Linux to the 8086, known as the Embeddable Linux
   Kernel Subset (ELKS). This is a 16-bit subset of the Linux kernel
   which will mainly be used for embedded systems. See
   http://www.linux.org.uk/Linux8086.html for more information.
   Linux will never run fully on an 8086 or '286, because it requires
   task-switching and memory management facilities not found on these
   processors.
   
   Linux supports multiprocessing with Intel MP architecture. See the
   file Documentation/smp.tex in the Linux kernel source code
   distribution.
   
   See the next question for a (probably incomplete) list of hardware
   platforms Linux has been ported to.
   
   
1.5 What ports to other processors are there?

   There is a reasonably complete list of Linux ports at
   http://www.ctv.es/USERS/xose/linux/linux_ports.html, and at
   http://www.linuxhq.com/dist-index.html.
   
   A project has been underway for a while to port Linux to suitable
   68000-series based systems like Amigas and Ataris. The Linux/m68K F
   is located at www.clark.net/pub/lawrencc/linux/faq/faq.html. The
   URL of the Linux/m68k home page is www.linux-m68k.
   
   There is a linux-680x0 mailing list. ("What mailing lists are
   there? ")
   
   There is (or was) a FTP site for the Linux-m68k project on
   ftp.phil.uni-sb.de/pub/atari/linux-68k, but this address may no
   longer be current.
   
   Debian GNU/Linux is being ported to Alpha, Sparc, PowerPC, and ARM
   platforms. There are mailing lists for all of them. See
   http://www.debian.org/MailingLists/subscribe.
   
   One of the Linux-PPC project pages has moved recently. Its location
   http://www.linuxppc.org, and the archive site is
   ftp.linuxppc.org/linuxppc.
   
   There is a Linux-PPC support page at www.cs.nmt.edu/~linuxppc/.
   There you will find the kernel that is distributed with Linux.
   
   Apple now supports MkLinux development on Power Macs, based on OSF 
   the Mach microkernel. See http://www.mklinux.apple.com.
   
   A port to the 64-bit DEC Alpha/AXP is at
   http://www.azstarnet.com/~axplinux/. There is a mailing list at
   vger.rutgers.edu. ("What mailing lists are there? ")
   
   Ralf Baechle is working on a port to the MIPS, initially for the R4
   on Deskstation Tyne machines. The Linux-MIPS FTP sites are
   ftp.fnet.fr/linux-mips and
   ftp://ftp.linux.sgi.com/pub/mips-linux. Interested people may
   mail their questions and offers of assistance to
   linux@waldorf-gmbh.de.
   
   There is also a MIPS channel on the Linux Activists mail server and
   linux-mips mailing list. ("What mailing lists are there? ")
   
   There are currently two ports of Linux to the ARM family of
   processors. One of these is for the ARM3, fitted to the Acorn A5000
   and it includes I/O drivers for the 82710/11 as appropriate. The ot
   is to the ARM610 of the Acorn RISC PC. The RISC PC port is currentl
   in its early to middle stages, owing to the need to rewrite much of
   the memory handling. The A5000 port is in restricted beta testing. 
   release is likely soon.
   
   For more, up-to-date information, read the newsgroup
   comp.sys.acorn.misc. There is a FAQ at
   http://www.arm.uk.linux.org
   
   The Linux SPARC project is a hotbed of activity. There is a FAQ
   available from Jim Mintha's Linux for SPARC Processors page,
   http://www.geog.ubc.ca/sparclinux.html. The SPARC/Linux archives
   are at vger.rutgers.edu/pub/linux/Sparc.
   
   There is also a port ("Hardhat") to SGI/Indy machines. The URL is
   http://www.linux.sgi.com.
   
   
1.6 How much hard disk space does Linux need?

   About 10Mb for a very minimal installation, suitable for trying Lin
   and not much else.
   
   You can fit an installation that includes X into 80Mb. Installing
   Debian GNU/Linux takes 500Mb--1GB, including kernel source code, so
   space for user files, and spool areas.
   
   
1.7 How much memory does Linux need?

   At least 4MB, and then you will need to use special installation
   procedures until the disk swap space is installed. Linux will run
   comfortably in 4MB of RAM, although X Windows Apps will run slowly
   because they need to swap out to disk.
   
   Some recent applications, like Netscape, require 64MB of physical
   memory.
   
   
1.8 How much memory can Linux use?

   A number of people have asked how to address more than 64 MB of
   memory, which is the default upper limit. Place the following in yo
   lilo.conf file:
append="mem=XXM"

   Where "XX" is the amount of memory, specified as megabytes; for
   example, '128M'. For further details, see the lilo manual page.
   
   
1.9 Is Linux public domain? Copyrighted?

   The Linux kernel copyright belongs to Linus Torvalds. He has placed
   under the GNU General Public License, which basically means that yo
   may freely copy, change, and distribute it, but you may not impose 
   restrictions on further distribution, and you must make the source
   code available.
   
   This is not the same as Public Domain. See the Copyright FAQ,
   rtfm.mit.edu/pub/usenet/news.answers/law/copyright, for details.
   
   Full details are in the file COPYING in the Linux kernel sources
   (probably in /usr/src/linux on your system).
   
   The licenses of the utilities and programs which come with the
   installations vary. Much of the code is from the GNU Project at the
   Free Software Foundation, and is also under the GPL.
   
   Note that discussion about the merits or otherwise of the GPL shoul
   be posted to the news group gnu.misc.discuss, and not to the
   comp.os.linux hierarchy.
   
   
   
   
2. Network sources and resources.

   
2.1 Where can I get the HOWTO's and other documentation?

   Look in the following places, and the sites that mirror them.
     * ftp.funet.fi : /pub/OS/Linux/doc/HOWTO
     * tsx-11.mit.edu : /pub/linux/docs/HOWTO
     * sunsite.unc.edu : /pub/Linux/docs/HOWTO
       
   For a complete list of Linux FTP sites, see, "Where can I get
   Linux material by FTP? "
   
   If you don't have access to FTP, try the FTP-by-mail servers at
   ftpmail@decwrl.dec.com, ftpmail@doc.ic.ac.uk, or
   ftp-mailer@informatik.tu-muenchen.de.
   
   A complete list of HOWTO's and Mini-HOWTO's is available in the fil
   HOWTO-INDEX in the docs/HOWTO directory at the FTP sites, and on th
   Web at http://sunsite.unc.edu/LDP/HOWTO/HOWTO-INDEX.html, but
   here is a (possibly incomplete) list:
AX25-HOWTO                             Access-HOWTO
Assembly-HOWTO                         Benchmarking-HOWTO
BootPrompt-HOWTO                       Bootdisk-HOWTO
CD-Writing-HOWTO                       CDROM-HOWTO
Chinese-HOWTO                          Commercial-HOWTO
Consultants-HOWTO                      Cyrillic-HOWTO
DNS-HOWTO                              DOS-to-Linux-HOWTO
DOSEMU-HOWTO                           Danish-HOWTO
Distribution-HOWTO                     ELF-HOWTO
Emacspeak-HOWTO                        Ethernet-HOWTO
Finnish-HOWTO                          Firewall-HOWTO
Ftape-HOWTO                            GCC-HOWTO
German-HOWTO                           HAM-HOWTO
HOWTO-INDEX                            Hardware-HOWTO
Hebrew-HOWTO                           IPX-HOWTO
ISP-Hookup-HOWTO                       Installation-HOWTO
Intranet-Server-HOWTO                  Italian-HOWTO
Java-CGI-HOWTO                         Kernel-HOWTO
Keyboard-and-Console-HOWTO             MGR-HOWTO
MILO-HOWTO                             Mail-HOWTO
NET-3-HOWTO                            NFS-HOWTO
NIS-HOWTO                              News-HOWTO
Optical-Disk-HOWTO                     PCI-HOWTO
PCMCIA-HOWTO                           PPP-HOWTO
Pilot-HOWTO                            Polish-HOWTO
Printing-HOWTO                         Printing-Usage-HOWTO
RPM-HOWTO                              Reading-List-HOWTO
SCSI-HOWTO                             SCSI-Programming-HOWTO
SMB-HOWTO                              Serial-HOWTO
Serial-Programming-HOWTO               Shadow-Password-HOWTO
Slovenian-HOWTO                        Sound-HOWTO
Sound-Playing-HOWTO                    Spanish-HOWTO
TeTeX-HOWTO                            Thai-HOWTO
Tips-HOWTO                             UMSDOS-HOWTO
UPS-HOWTO                              UUCP-HOWTO
User-Group-HOWTO                       VAR-HOWTO
VMS-to-Linux-HOWTO                     XFree86-HOWTO
XFree86-Video-Timings-HOWTO
3-Button-Mouse

   The following Mini-HOWTO's are available from
   http://sunsite.unc.edu/pub/Linux/HOWTO/mini:
ADSM-Backup                            AI-Alife
Advocacy                               Backup-With-MSDOS
Battery-Powered                        Boca
BogoMips                               Bridge
Bridge+Firewall                        Clock
Colour-ls                              Comeau-C++
DHCPd                                  Dial-On-Demand
Diald                                  Dip+SLiRP+CSLIP
Diskless                               Dynamic-IP-Hacks
Ext2fs-Undeletion                      GTEK-BBS-550
HTML-Validation                        IO-Port-Programming
IP-Alias                               IP-Masquerade
IP-Subnetworking                       JE
Jaz-Drive                              Kerneld
Key-Setup                              LBX
Large-Disk                             Linux+DOS+Win95
Linux+DOS+Win95+OS2                    Linux+NT-Loader
Linux+OS2+DOS                          Linux+Win95
Loadlin+Win95                          Locales
MIDI+SB                                Mail-Queue
Mail2News                              Man-Page
Multiple-Disks-Layout                  Multiple-Ethernet
NFS-Root                               NFS-Root-Client
Netscape+Proxy                         Offline-Mailing
Online-Support                         PLIP
PPP-over-minicom                       Pager
Partition                              Print2Win
Process-Accounting                     Proxy-ARP
Public-Web-Browser                     Qmail+MH
Quota                                  RCS
Remote-Boot                            Remote-X-Apps
SLIP+proxyARP                          SLIP-PPP-Emulator
Sendmail+UUCP                          Software-Building
Software-RAID                          Soundblaster-16
Soundblaster-AWE64                     StarOffice
Swap-Space                             Term-Firewall
Tiny-News                              Token-Ring
Upgrade                                VPN
Virtual-wu-ftpd                        Visual-Bell
Win95+Win+Linux                        Windows-Modem-Sharing
WordPerfect                            X-Big-Cursor
XFree86-XInside                        Xterm-Title
Xterminal                              ZIP-Drive
ZIP-Install

   In addition, translations of the HOWTO's are available from
   sunsite.unc.edu/pub/Linux/docs/HOWTO/translations and mirrors
   worldwide. Translations in the following languages are available:
   
Chinese (zh)                    Croatian(hr)
French (fr)                     German (de)
Hellenic (el)                   Indonesian (id)
Italian (it)                    Japanese (jp)
Korean (ko)                     Polish (pl)
Spanish (es)                    Slovenian (sl)
Swedish (sv)                    Turkish (tr)

   The HOWTO's are also on the Web, at the Linux Documentation Project
   Home Page, http://sunsite.unc.edu/LDP.
   
   More of these documents are always in preparation. Please get in to
   with Timothy Bynum, tjbynum@sunsite.unc.edu, the HOWTO
   coordinator, if you are interested in writing one. The file
   sunsite.unc.edu/pub/Linux/HOWTO/HOWTO-INDEX contains guidelines
   for writing a HOWTO. He has a Web page that lists current HOWTO
   updates and additions at
   wallybox.cei.net/~tjbynum/HOWTO/projects.
   
   The Guide Series produced by the Linux Documentation Project is
   available from http://sunsite.unc.edu/LDP. Please read them if
   you are new to Unix and Linux. Here is a list of those available so
   far:
   
     * The Linux Documentation Project Manifesto, by Matt Welsh.
     * Installation and Getting Started Guide, by Matt Welsh.
     * The Linux Kernel, by David Rusling.
     * The Network Administrator's Guide, by Olaf Kirch.
     * The Linux Programmer's Guide, by Sven Goldt, Sven van der
       Meer, Scott Burkett, and Matt Welsh.
     * The Linux System Administrator's Guide, Version 0.5, by Lars
       Wirzenius.
       
   In addition, there is a FAQ for Linux kernel developers at
   http://www.tux.org/html/.
   
   
2.2 Where should I look on the World Wide Web for Linux stuff?

   Two Web pages in particular provide good starting point for general
   Linux information: Linux International's Home Page, at
   http://www.li.org, and the Linux Online's Linux Home Page at
   http://www.linux.org/.
   
   Both of these pages provide links to other sites, information about
   general information, distributions, new software, documentation, an
   news.
   
   Greg Hankins, gregh@cc.gatech.edu, maintains the Linux
   Documentation Project Home Page, at http://sunsite.unc.edu/LDP.
   This page refers to all of the HOWTO's and FAQ's, both those which 
   available in HTML (WWW) format, and those which aren't.
   
   
2.3 What newsgroups are there for Linux?

   Comp.os.linux.announce is the moderated announcements group; you
   should read this if you intend to use Linux: it contains informatio
   about software updates, new ports, user group meetings, and commerc
   products. It is the ONLY newsgroup that may carry commercial postin
   Submissions for that group should be e-mailed to
   linux-announce@news.ornl.gov.
   
   comp.os.linux.announce, however, is not archived on DejaNews or Alt
   Vista. The only archive for the news group seems to be
   www.iki.fi/mjr/linux/cola.html.
   
   [Axel Boldt]
   
   Also worth reading are the following other groups in the
   comp.os.linux.* hierarchy--you may find many common problems too
   recent for the documentation but are answered in the newsgroups.
comp.os.linux.setup
comp.os.linux.hardware
comp.os.linux.networking
comp.os.linux.x
comp.os.linux.development.apps
comp.os.linux.development.system
comp.os.linux.advocacy
comp.os.linux.misc

   Remember that Linux is POSIX compatible, and most all of the materi
   in comp.unix.* and comp.windows.x.* groups will be relevant. Apart
   from hardware considerations, and some obscure or very technical
   low-level issues, you'll find that these groups are good places to
   start.
   
   Please read "You still haven't answered my question! " before
   posting. Cross posting between different comp.os.linux.* groups is
   rarely a good idea.
   
   There may well be Linux groups local to your institution or
   area--check there first.
   
   See also "I don't have Usenet access. Where do I get
   information? "
   
   Other regional and local newsgroups also exist--you may find the
   traffic more manageable there. The French Linux newsgroup is
   fr.comp.os.linux. The German one is de.comp.os.linux. In Australia,
   try aus.computers.linux. In Croatia there is hr.comp.linux. In Ital
   there is it.comp.linux.
   
   
2.4 Where can I find out about Linux and the Millennium (Y2K) bug?

   The Debian/GNU Linux people have a statement on their Web site at
   http://www.debian.org
   
   Essentially, Linux uses libraries that store dates as 32-bit intege
   which count the seconds since 1970. This counter will not overflow
   until the year 2038, by which time the library programmers will
   (hopefully) have upgraded the system software to store dates as 64-
   integers.
   
   This, of course, does not mean that applications are not susceptibl
   to the millennium bug, if they do not use the standard library
   routines.
   
   The Free Software Foundation has a Web page about Y2K issues in GNU
   software at http://www.fsf.org/software/year2000.html
   
   There is also a Usenet newsgroup, comp.software.year-2000, for gene
   discussion of Y2K issues.
   
   
2.5 Where can I get Linux material by FTP?

   There are three main archive sites for Linux:
     * ftp.funet.fi (Finland) : /pub/OS/Linux
     * sunsite.unc.edu (US) : /pub/Linux
     * tsx-11.mit.edu (US) : /pub/linux
       
   The best place to get the Linux kernel is
   ftp.cs.helsinki.fi/pub/Linux_Kernel. Linus Torvalds uploads the
   most recent kernel versions to this site.
   
   Of the U.S. distributions, Debian GNU/Linux is available at
   ftp.debian.org/pub/debian. Red Hat Linux's home site is
   ftp.redhat.com, and Linux Slackware's is ftp.cdrom.com.
   
   The contents of these sites is mirrored (copied, usually approximat
   daily) by a number of other sites. Please use a site close to you--
   will be faster for you and easier on the network.
     * ftp.sun.ac.za/pub/linux/sunsite/ (South Africa)
     * ftp.is.co.za/linux/sunsite/ (South Africa)
     * ftp.cs.cuhk.hk/pub/Linux/ (Hong Kong)
     * ftp.cs.cuhk.hk/pub/Linux/ (Hong Kong)
     * ftp.spin.ad.jp/pub/linux/sunsite.unc.edu/ (Japan)
     * ftp.nuri.net/pub/Linux/ (Korea)
     * ftp.jaring.my/pub/Linux/ (Malaysia)
     * ftp.nus.sg/pub/unix/Linux/ (Singapore)
     * ftp.nectec.or.th/pub/mirrors/linux/ (Thailand)
     * mirror.aarnet.edu.au/pub/linux/ (Australia)
     * sunsite.anu.edu.au/pub/linux/ (Australia)
     * ftp.monash.edu.au/pub/linux/ (Australia)
     * ftp.univie.ac.at/systems/linux/sunsite/ (Austria)
     * ftp.fi.muni.cz/pub/UNIX/linux/ (Czech Republic)
     * ftp://sunsite.fri.uni-lj.si/pub/linux/ (Slovenia)
     * ftp.funet.fi/pub/Linux/sunsite/ (Finland)
     * ftp.univ-angers.fr/pub/Linux/ (France)
     * ftp.iut-bm.univ-fcomte.fr (France)
     * ftp.ibp.fr/pub/linux/sunsite/ (France)
     * ftp.loria.fr/pub/linux/sunsite/ (France)
     * ftp.dfv.rwth-aachen.de/pub/linux/sunsite/ (Germany)
     * ftp.germany.eu.net/pub/os/Linux/Mirror.SunSITE/ (Germany)
     * ftp.tu-dresden.de/pub/Linux/sunsite/ (Germany)
     * ftp.uni-erlangen.de/pub/Linux/MIRROR.sunsite/ (Germany)
     * ftp.gwdg.de/pub/linux/mirrors/sunsite/ (Germany)
     * ftp.rz.uni-karlsruhe.de/pub/linux/mirror.sunsite/ (Germany)
     * ftp.ba-mannheim.de/pub/linux/mirror.sunsite/ (Germany)
     * ftp.uni-paderborn.de/pub/Mirrors/sunsite.unc.edu/ (Germany)
     * ftp.uni-rostock.de/Linux/sunsite/ (Germany)
     * tp.rus.uni-stuttgart.de/pub/unix/systems/linux/MIRROR.sunsite
       / (Germany)
     * ftp.uni-tuebingen.de/pub/linux/Mirror.sunsite/ (Germany)
     * ftp.rz.uni-ulm.de/pub/mirrors/linux/sunsite/ (Germany)
     * ftp.kfki.hu/pub/linux/ (Hungary)
     * linux.italnet.it/pub/Linux/ (Italy)
     * ftp.unina.it/pub/linux/sunsite/ (Italy)
     * giotto.unipd.it/pub/unix/Linux/ (Italy)
     * cnuce-arch.cnr.it/pub/Linux/ (Italy)
     * ftp.flashnet.it/mirror2/sunsite.unc.edu/ (Italy)
     * ftp.nijenrode.nl/pub/linux/sunsite.unc-mirror/ (Netherlands)
     * ftp.LeidenUniv.nl/pub/linux/sunsite/ (Netherlands)
     * ftp.nvg.unit.no/pub/linux/sunsite/ (Norway)
     * ftp://sunsite.icm.edu.pl/pub/Linux/sunsite.unc.edu/ (Poland)
     * ftp.rediris.es/software/os/linux/sunsite/ (Spain)
     * sunsite.rediris.es/software/linux/ (Spain)
     * ftp.cs.us.es/pub/Linux/sunsite-mirror/ (Spain)
     * ftp.etse.urv.es/pub/mirror/linux/ (Spain)
     * ftp.etsimo.uniovi.es/pub/linux/ (Spain)
     * ftp.luna.gui.es/pub/linux.new/ (Spain)
     * ftp.switch.ch/mirror/linux/ (Switzerland)
     * ftp.metu.edu.tr/pub/linux/sunsite/ (Turkey)
     * unix.hensa.ac.uk/mirrors/sunsite/pub/Linux/ (UK)
     * ftp.maths.warwick.ac.uk/mirrors/linux/sunsite.unc-mirror/
       (UK)
     * ftp.idiscover.co.uk/pub/Linux/sunsite.unc-mirror/ (UK)
     * sunsite.doc.ic.ac.uk/packages/linux/sunsite.unc-mirror/ (UK)
     * ftp.dungeon.com/pub/linux/sunsite-mirror/ (UK)
     * ftp.io.org/pub/mirrors/linux/sunsite/ (Canada)
     * ftp.cc.gatech.edu/pub/linux/ (US)
     * ftp.cdrom.com/pub/linux/sunsite/ (US)
     * ftp.siriuscc.com/pub/Linux/Sunsite/ (US)
     * ftp.engr.uark.edu/pub/linux/sunsite/ (US)
     * ftp.infomagic.com/pub/mirrors/linux/sunsite/ (US)
     * linux.if.usp.br/pub/mirror/sunsite.unc.edu/pub/Linux/
       (Brazil)
     * farofa.ime.usp.br/pub/linux/ (Brazil)
       
   Not all of these mirror all of the other "source" sites, and some
   have material not available on the "source" sites.
   
   
2.6 I don't have FTP access. Where do I get Linux?

   The easiest thing is probably to find a friend with FTP access. If
   there is a Linux user's group near you, they may be able to help.
   
   If you have a reasonably good email connection, you could try the
   FTP-by-mail servers at ftpmail@ftp.sunet.se,
   ftpmail@garbo.uwasa.fi, or ftpmail@ftp.uni-stuttgart.de.
   
   Linux is also available via traditional mail on CD-ROM. The file
   sunsite.unc.edu/pub/Linux/docs/HOWTO/Installation-HOWTO, and the
   file sunsite.unc.edu/pub/Linux/docs/HOWTO/Distribution-HOWTO
   contain information on these distributions.
   
   
2.7 I don't have Usenet access. Where do I get information?

   A digest of comp.os.linux.announce is available by mailing the word
   "subscribe" (without the quotes) as the body of a message to
   linux-announce-REQUEST@news-digests.mit.edu. Subscribing to this
   list is a good idea, as it carries important information and
   documentation about Linux.
   
   Please remember to use the *-request addresses for your subscribe a
   unsubscribe messages; mail to the other address is posted to the ne
   group.
   
   
2.8 What mailing lists are there?

   The Linux developers now mainly use the Majordomo server at
   majordomo@vger.rutgers.edu. Send a message with the word
   "lists" (without the quotes) in the body to get a list of lists
   there. Add a line with the word, "help," to get the standard
   Majordomo help file that lists instructions for subscribing and
   unsubscribing to the lists.
   
   Most of the lists are used by Linux developers to talk about techni
   issues and future developments. These are not intended for new user
   questions.
   
   There is a linux-newbie list where, "no question is too stupid."
   Unfortunately, it seems that few experienced users read that list, 
   it has very low volume.
   
   
2.9 Are the newsgroups archived anywhere?

   The Usenet Linux news groups are archived at
   http://www.dejanews.com, http://www.reference.com, and
   http://altavista.digital.com
   
   Sunsite.unc.edu/pub/Linux/docs/linux-announce.archive contains
   archives of comp.os.linux.announce. These are mirrored from
   src.doc.ic.ac.uk/usenet, which also archives comp.os.linux,
   comp.os.linux.development.apps, and comp.os.linux.development.syste
   
   There is an `easy to access' archive of comp.os.linux.announce on t
   World Wide Web at
   http://www.leo.org/archiv/linux/archiv/ann_index.html which
   supports searching and browsing.
   
   
   contents
   
   
3. Compatibility with other operating systems.

   
3.1 Can Linux share my disk with DOS? OS/2? 386BSD? Win95?

   Yes. Linux uses the standard MS-DOS partitioning scheme, so it can
   share your disk with other operating systems. Note, however, that m
   other operating systems may not be exactly compatible. DOS's FDISK.
   and FORMAT.EXE, for example, can overwrite data in a Linux partitio
   because they sometimes incorrectly use partition data from the
   partition's boot sector rather than the partition table.
   
   In order to prevent programs from doing this, it is a good idea to
   zero out--under Linux--the start of a partition you created, before
   you use MS-DOS--or whatever--to format it. Type:
$ dd if=/dev/zero of=/dev/hdXY bs=512 count=1

   where hdXY is the relevant partition; e.g., /dev/hda1 for the first
   partition of the first (IDE) disk.
   
   Linux can read and write the files on your DOS and OS/2 FAT partiti
   and floppies using either the DOS file system type built into the
   kernel or mtools. There is kernel support for the VFAT file system
   used by Windows 9x and Windows NT.
   
   For information about FAT32 partition support, see
   http://bmrc.berkeley.edu/people/chaffee/fat32.html.
   
   See, "What software does Linux support? " for details and
   status of the emulators for DOS, MS Windows, and System V programs.
   
   See also, "Can Linux access Amiga file systems? ", "Can
   Linux access Macintosh file systems? ", "Can Linux access BSD,
   SysV, etc., UFS? ", and "Can Linux access SMB file systems? "
   
   There are said to be NTFS drivers under development, which should
   support compression as a standard feature.
   
   
3.2 How do I access files on my DOS partition or floppy?

   Use the DOS file system, type, for example:
$ mkdir /dos
$ mount -t msdos -o conv=text,umask=022,uid=100,gid=100 /dev/hda3 /dos

   If it's a floppy, don't forget to umount it before ejecting it!
   
   You can use the conv=text/binary/auto, umask=nnn, uid=nnn, and gid=
   options to control the automatic line-ending conversion, permission
   and ownerships of the files in the DOS file system as they appear
   under Linux. If you mount your DOS file system by putting it in you
   /etc/fstab, you can record the options (comma-separated) there,
   instead of defaults.
   
   Alternatively, you can use mtools, available in both binary and sou
   form on the FTP sites. ("Where can I get Linux material by FTP?
   ")
   
   A kernel patch (known as the fd-patches) is available which allows
   floppies with nonstandard numbers of tracks and/or sectors to be us
   this patch is included in the 1.1 alpha testing kernel series.
   
   
3.3 Does Linux support compressed ext2 file systems?

   As of recently, it does. Information about them is located at
   http://www.netspace.net.au/~reiter/e2compr/.
   
   There is also a Web site for the e2compr patches The code is still
   experimental and consists of patches for the 2.0 and 2.1 kernels. F
   more information about the project, including the latest patches, a
   the address of the mailing list, look up the URL at
   http://debs.fuller.edu/e2compr/.
   
   [Roderich Schupp]
   
   Zlibc is a program that allows existing applications to read
   compressed (GNU gzip'ed) files as if they were not compressed. Look
   sunsite.unc.edu in /pub/Linux/libs/. The author is Alain Knuff.
   
   There is also a compressing block device driver, "DouBle," by
   Jean-Marc Verbavatz, which can provide on-the-fly disk compression 
   the kernel. The source-only distribution is located at sunsite.unc.
   in the directory /pub/Linux/patches/diskdrives/. This driver
   compresses inodes and directory information as well as files, so an
   corruption of the file system is likely to be serious.
   
   There is also a package called tcx (Transparently Compressed
   Executables), which allows you to keep infrequently compressed
   executables compressed and only uncompress them temporarily when in
   use. It is located on sunsite.unc.edu in the directory
   /pub/Linux/utils/compress/.
   
   
3.4 Can I use my Stacked/DBLSPC/etc. DOS drive?

   Until recently, not very easily. You can access DOS 6.X volumes fro
   the DOS emulator ("What software does Linux support? "), but
   it's harder than accessing a normal DOS volume via the DOS kernel
   option, a module, or mtools.
   
   There is a recently added package, dmsdos, which reads and writes
   compressed file systems like DoubleSpace/DriveSpace in MS-DOS 6.x a
   Win95, as well as Stacker versions 3 and 4. It is available in the
   archives on
   ftp://sunsite.unc.edu/pub/Linux/system/Filesystem/dosfs.
   
   There is a module available for the Linux kernel which can do
   read-only access of compressed volume. Look at
   sunsite.unc.edu/pub/Linux/system/filesystems/dosfs/.
   
   
3.5 Can I access OS/2 HPFS partitions from Linux?

   Yes, but Linux access to HPFS partitions is read-only. HPFS file
   system access is available as an option when compiling the kernel o
   as a module. See the Documentation/filesystems/hpfs.txt file in the
   kernel source distribution. ("How do I upgrade/recompile my
   kernel? ") Then you can mount HPFS partition, using, for example:
$ mkdir /hpfs
$ mount -t hpfs /dev/hda5 /hpfs

   
3.6 Can Linux access Amiga file systems?

   The Linux kernel has support for the Amiga Fast File System (AFFS)
   version 1.3 and later, both as a compile-time option and as a modul
   The file Documentation/filesystems/affs.txt in the Linux kernel sou
   distribution has more information.
   
   See "How do I upgrade/recompile my kernel? ".
   
   Linux supports AFFS hard-drive partitions only. Floppy access is no
   supported due to incompatibilities between Amiga floppy controllers
   and PC and workstation controllers. The AFFS driver can also mount
   disk partitions used by the Un*x Amiga Emulator, by Bernd Schmidt.
   
   
3.7 Can Linux access BSD, SysV, etc. UFS?

   Recent kernels can mount (read only) the UFS file system used by
   System V; Coherent; Xenix; BSD; and derivatives like SunOS, FreeBSD
   NetBSD, and NeXTStep. UFS support is available as a kernel
   compile-time option and a module.
   
   See, "How do I upgrade/recompile my kernel? "
   
   
3.8 Can Linux access SMB file systems?

   Linux supports read/write access of Windows for Workgroups and Wind
   NT SMB volumes. See the file Documentation/filesystems/smbfs.txt of
   the Linux kernel source distribution, and "How do I
   upgrade/recompile my kernel? " in this FAQ.
   
   There is also a suite of programs called Samba which provide suppor
   for WfW networked file systems (provided they're for TCP/IP).
   Information is available in the README file at
   sunsite.unc.edu/pub/Linux/system/network/samba/.
   
   There is a SMB Web site at samba.anu.edu.au/samba/.
   
   
3.9 Can Linux access Macintosh file systems?

   There is a set of user-level programs that read and write the
   Macintosh Hierarchical File System (HFS). It is available at
   sunsite.unc.edu/pub/Linux/utils/disk-management.
   
   
3.10 Can I run Microsoft Windows programs under Linux?

   WINE, a MS Windows emulator for Linux, is still not ready for gener
   distribution. If you want to contribute to its development, look fo
   the status reports in the comp.emulators.ms-windows.wine newsgroup.
   
   There is also a FAQ, compiled by P. David Gardner, at
   sunsite.unc.edu/pub/Linux/docs/faqs/Wine-FAQ/.
   
   In the meantime, if you need to run MS Windows programs, the best
   bet--seriously--is to reboot. LILO, the Linux boot loader, can boot
   one of several operating systems from a menu. See the LILO
   documentation for details.
   
   Also, LOADLIN (a DOS program to load a Linux, or other OS, kernel i
   one way to make Linux co-exist with DOS. LOADLIN is particularly ha
   when you want to install Linux on a 3rd or 4th drive on a system (o
   when you're adding a SCSI drive to a system with an existing IDE).
   
   In these cases, it is common for LILO's boot loader to be unable to
   find or load the kernel on the "other" drive. So you just create a
   C:\LINUX directory (or whatever), put LOADLIN in it with a copy of
   your kernel, and use that.
   
   LOADLIN is a VCPI compliant program. Win95 will want to, "shutdown
   into DOS mode," to run it (as it would with certain other DOS
   protected-mode programs).
   
   Earlier versions of LOADLIN sometimes required a package called
   REALBIOS.COM, which required a boot procedure on an (almost) blank
   floppy to map the REALBIOS interrupt vectors (prior to the loading 
   any software drivers). (Current versions don't seem to ship with it
   and don't seem to need it).
   
   [Jim Dennis]
   
   
3.11 How can I boot Linux from OS/2's Boot Manager?

    1. Create a partition using OS/2's FDISK.EXE (Not Linux's fdisk).
    2. Format the partition under OS/2, either with FAT or HPFS. This 
       so that OS/2 knows about the partition being formatted. (This s
       is not necessary with OS/2 `warp' 3.0.)
    3. Add the partition to the Boot Manager.
    4. Boot Linux, and create a file system on the partition using mkf
       -t ext2 or mke2fs. At this point you may, if you like, use Linu
       fdisk to change the code of the new partition to type 83 (Linux
       Native)--this may help some automated installation scripts find
       the right partition to use.
    5. Install Linux on the partition.
    6. Install LILO on the Linux partition--NOT on the master boot rec
       of the hard drive. This installs LILO as a second-stage boot
       loader on the Linux partition itself, to start up the kernel
       specified in the LILO configuration file. To do this, you shoul
       put
boot = /dev/hda2
       (where /dev/hda2 is the partition you want to boot from) in you
       /etc/lilo/config or /etc/lilo.config file.
    7. Make sure that it is the Boot Manager partition that is marked
       active, so that you can use Boot Manager to choose what to boot
       
   There is a set of HOWTO's on the subject of multi-boot systems on t
   LDP Home Page, http://sunsite.unc.edu/LDP/.
   
   
3.12 How can I share a swap partition between Linux and MS Windows?

   See the Mini-HOWTO on the subject. The Mini-HOWTO is currently
   unmaintained but is available at
   ftp://sunsite.unc.edu/pub/Linux/docs/HOWTO/mini/unmaintained.
   
   
   contents
   
   
4. Linux's handling of file systems, disks, and drives

   
4.1 How can I get Linux to work with my disk?

   If your disk is an IDE or EIDE drive, you should read the file
   /usr/src/linux/drivers/block/README.ide (part of the Linux kernel
   source code). This README contains many helpful hints about IDE
   drives. Many modern IDE controllers do translation between `physica
   cylinders/heads/sectors, and `logical' ones.
   
   SCSI disks are accessed by linear block numbers. The BIOS invents s
   `logical' cylinder/head/sector fiction to support DOS.
   
   An IBM PC-compatible BIOS will usually not be able to access
   partitions which extend beyond 1024 logical cylinders, and will mak
   booting a Linux kernel from such partitions using LILO problematic 
   best.
   
   You can still use such partitions for Linux or other operating syst
   that access the controller directly.
   
   It's recommend that you create at least one Linux partition entirel
   under the 1024 logical cylinder limit, and boot from that. The othe
   partitions will then be okay.
   
   Also there seems to be a bit of trouble with the newer Ultra-DMA
   drives. I haven't gotten the straight scoop on them--but they are
   becoming a very common problem at the SVLUG installfests. When you 
   get 8 to 12 Gig drives for $200 to $300 it's no wonder.
   
   [Jim Dennis]
   
   
4.2 How can I undelete files?

   In general, this is very hard to do on Unices because of their
   multitasking nature. Undelete functionality for the ext2fs file sys
   is being worked on, but don't hold your breath.
   
   There are a number of packages available which instead provide new
   commands for deleting and copying which move deleted files into a
   `wastebasket' directory. The files can be recovered until cleaned o
   automatically by background processing.
   
   Alternatively, you can search the raw disk device which holds the f
   system in question. This is hard work, and you will need to be logg
   in as root to do this.
   
   
4.3 Is there a defragmenter for ext2fs etc.?

   Yes. There is defrag, a Linux file system defragmenter for ext2,
   Minix, and old-style ext file systems. It is available at
   sunsite.unc.edu/pub/Linux/system/filesystems/defrag-0.70.tar.gz.
   
   Users of the ext2 file system can probably do without defrag, becau
   ext2 contains extra code to keep fragmentation reduced even in very
   full file systems.
   
   
4.4 How do I format and create a file system on a floppy?

   To format a 3.5-inch, high density floppy:
$ fdformat /dev/fd0H1440
$ mkfs -t ext2 -m 0 /dev/fd0H1440 1440

   For a 5.25 inch floppy, use fd0h1200 and 1200 as appropriate. For t
   `B' drive use fd1 instead of fd0.
   
   The -m 0 option tells mkfs.ext2 not to reserve any space on the dis
   for the superuser--usually the last 10% is reserved for root.
   
   The first command performs a low-level format. The second creates a
   empty file system. You can mount the floppy like a hard disk partit
   and simply cp and mv files, etc.
   
   Device naming conventions generally are the same as for other Unice
   They can be found in Matt Welsh's Installation and Getting Started
   Guide. (See "Where can I get the HOWTO's and other
   documentation? ") A more detailed and technical description is Linu
   Allocated Devices by H. Peter Anvin, hpa@zytor.com, which is
   included in LaTeX and ASCII form in the kernel source distribution
   (probably in /usr/src/kernel/Documentation), as devices.tex and
   devices.txt.
   
   
4.5 I get nasty messages about inodes, blocks, and the like.

   You may have a corrupted file system, probably caused by not shutti
   Linux down properly before turning off the power or resetting. You
   need to use a recent shutdown program to do this--for example, the 
   included in the util-linux package, available on sunsite and tsx-11
   
   If you're lucky, the program fsck (or e2fsck or xfsck as appropriat
   if you don't have the automatic fsck front-end) will be able to rep
   your file system. If you're unlucky, the file system is trashed, an
   you'll have to re-initialize it with mkfs (or mke2fs, mkxfs, etc.),
   and restore from a backup.
   
   NB: don't try to check a file system that's mounted read/write--thi
   includes the root partition, if you don't see
   VFS: mounted root ... read-only

   at boot time.
   
   
4.6 My swap area isn't working.

   When you boot (or enable swapping manually) you should see
        Adding Swap: NNNNk swap-space

   If you don't see any messages at all you are probably missing
swapon -av

   (the command to enable swapping) in your /etc/rc.local or /etc/rc.d
   (the system startup scripts), or have forgotten to make the right
   entry in /etc/fstab:
   
/dev/hda2       none       swap       sw

   for example.
   
   If you see
Unable to find swap-space signature

   you have forgotten to run mkswap. See the manual page for details; 
   works much like mkfs.
   
   Running, 'free' in addition to showing free memory, should display:
             total       used       free
Swap:        10188       2960       7228

   [Andy Jefferson]
   
   Take a look also at the Installation HOWTO for detailed instruction
   of how to set up a swap area.
   
   
4.7 How do I remove LILO so my system boots DOS again?

   Using DOS (MS-DOS 5.0 or later, or OS/2), type FDISK /MBR (which is
   not documented). This will restore a standard MS-DOS Master Boot
   Record. If you have DR-DOS 6.0, go into FDISK in the normal way and
   then select the `Re-write Master Boot Record' option.
   
   If you don't have MS-DOS or DR-DOS, you need to have the boot secto
   that LILO saved when you first installed it. You did keep that file
   didn't you? It's probably called boot.0301 or some such. Type
   dd if=boot.0301 of=/dev/hda bs=445 count=1

   (or /dev/sda if you're using a SCSI disk). This may also wipe out y
   partition table, so beware! If you're desperate, you could use
   dd if=/dev/zero of=/dev/hda bs=512 count=1

   This will erase your partition table and boot sector completely: yo
   can then reformat the disk using your favorite software. But this w
   render the contents of your disk inaccessible--you'll lose it all
   unless you're an expert.
   
   Note that the DOS MBR boots whichever (single!) partition is flagge
   as `active'. You may need to use fdisk to set and clear the active
   flags on partitions appropriately.
   
   
4.8 Why can't I use fdformat except as root?

   The system call to format a floppy can only be done as root,
   regardless of the permissions of /dev/fd0*. If you want any user to
   able to format a floppy, try getting the fdformat2 program. This wo
   around the problems by being setuid to root.
   
   
4.9 My ext2fs partitions are checked each time I reboot.

   See "EXT2-fs: warning: mounting unchecked file system.".
   
   
4.10 My root file system is read-only!

   Remount it. If /etc/fstab is correct, you can simply
mount -n -o remount /

   If /etc/fstab is wrong, you must give the device name and possibly 
   type, too: e.g.
mount -n -o remount -t ext2 /dev/hda2 /

   To understand how you got into this state, see, "EXT2-fs:
   warning: mounting unchecked file system."
   
   
4.11 I have a huge /proc/kcore! Can I delete it?

   None of the files in /proc are really there--they're all, "pretend,
   files made up by the kernel, to give you information about the syst
   and don't take up any hard disk space.
   
   /proc/kcore is like an `alias' for the memory in your computer. Its
   size is the same as the amount of RAM you have, and if you read it 
   a file, the kernel does memory reads.
   
   
4.12 My AHA1542C doesn't work with Linux.

   The option to allow disks with more than 1024 cylinders is only
   required as a workaround for a PC-compatible BIOS misfeature and
   should be turned `off' under Linux. For older Linux kernels you nee
   to turn off most of the `advanced BIOS' options--all but the one ab
   scanning the bus for bootable devices.
   
   
   contents
   
   
5. Porting, compiling and obtaining programs

   
5.1 How do I compile programs?

   Most Linux software is written in C and compiled with the GNU C
   compiler. GCC is a part of every Linux distribution. The latest
   compiler version, documentation, and patches are on
   ftp://ftp.gnu.org/pub/gnu/.
   
   Programs that are written in C++ must be compiled with the GNU G++
   compiler, which is also included in Linux distributions and availab
   from the same place as GCC.
   
   To build version 2.0.x kernels, you will need GCC version 2.7.2.x.
   Trying to build a Linux kernel with a different compiler, like GCC
   2.8.x, EGCS, or PGCC, may cause problems until code dependencies of
   the 2.7.2.x compilers are fixed.
   
   Information on the EGCS compiler is at htmlurl
   url="http://egcs.cygnus.com" name="http://egcs.cygnus.com">.
   
   Note that at this time, the kernel developers are not answering bug
   requests for 2.0.x version kernels, but instead are concentrating o
   developing 2.1.x version kernels.
   
   [J.H.M. Dassen]
   
   
5.2 How do I port XXX to Linux?

   In general, Unix programs need very little porting. Simply follow t
   installation instructions. If you don't know--and don't know how to
   find out--the answers to some of the questions asked during the
   installation procedure, you can guess, but this tends to produce bu
   programs. In this case, you're probably better off asking someone e
   to do the port.
   
   If you have a BSD-ish program, you should try using -I/usr/include/
   and -lbsd on the appropriate parts of the compilation lines.
   
   
5.3 What is ld.so and where do I get it?

   Ld.so is the dynamic library loader. Each binary using shared
   libraries used to have about 3K of start-up code to find and load t
   shared libraries. Now that code has been put in a special shared
   library, /lib/ld.so, where all binaries can look for it, so that it
   wastes less disk space, and can be upgraded more easily.
   
   Ld.so can be obtained from tsx-11.mit.edu/pub/linux/packages/GCC/
   and mirror sites. The latest version at the time of writing is
   ld.so.1.9.5.tar.gz.
   
   /lib/ld-linux.so.1 is the same thing for ELF ("What's all this
   about ELF? ") and comes in the same package as the a.out loader.
   
   
5.4 How do I upgrade the libraries withough trashing my system?

   Note: You should always have a rescue disk set ready when you perfo
   this procedure, in the likely event that something goes wrong!
   
   This procedure is especially difficult if you're upgrading very old
   libraries like libc4. But you should be able to keep libc4 on the s
   system with libc5 libraries for the programs that still need them. 
   same holds true for upgrading from libc5 to the newer-yet glibc2
   libraries.
   
   The problem with upgrading dynamic libraries is that, the moment yo
   remove the old libraries, the utilities that you need to upgrade to
   the new version of the libraries don't work. There are ways around
   around this. One is to temporarily place a spare copy of the run ti
   libraries, which are in /lib/, in /usr/lib/, or /usr/local/lib/, or
   another directory that is listed in the /etc/ld.so.conf file.
   
   For example, when upgrading libc5 libraries, the files in /lib/ mig
   look something like:
   
libc.so.5
libc.so.5.4.33
libm.so.5
libm.so.5.0.9

   These are the C libraries and the math libraries. Copy them to anot
   directory that is listed in /etc/ld.so.conf, like /usr/lib/.
   
cp -df /lib/libc.so.5* /usr/lib/
cp -df /lib/libm.so.5* /usr/lib/
ldconfig

   Be sure to run ldconfig to upgrade the library configuration.
   
   The files libc.so.5 and libm.so.5 are symbolic links to the actual
   library files. When you upgrade, the new links will not be created 
   the old links are still there, unless you use the -f flag with cp. 
   -d flag to cp will copy the symbolic link itself, and not the file 
   points to.
   
   If you need to overwrite the link to the library directly, use the 
   flag with ln.
   
   For example, to copy new libraries over the old ones, try this. Mak
   symbolic link to the new libraries first, then copy both the librar
   and the links to /lib/, with the following commands.
ln -sf ./libm.so.5.0.48 libm.so.5
ln -sf ./libc.so.5.0.48 libc.so.5
cp -df libm.so.5* /lib
cp -df libc.so.5* /lib

   Again, remember to run ldconfig after you copy the libraries.
   
   If you are satisfied that everything is working correctly, you can
   remove the temporary copies of the old libraries from /usr/lib/ or
   wherever you copied them.
   
   
5.5 Has anyone ported / compiled / written XXX for Linux?

   First, look in the Linux Software Map--it's at
   sunsite.unc.edu/pub/Linux/docs/linux-software-map, and on the
   other FTP sites. A search engine is available on the World Wide Web
   http://www.boutell.com/lsm/.
   
   Check the FTP sites ("Where can I get Linux material by FTP?
   ") first--search the ls-lR or INDEX files for appropriate strings.
   
   Also look at the Linux Projects Map,
   ftp.ix.de/pub/ix/Linux/docs/Projects-Map.gz.
   
   There's a search engine for Linux FTP archives at
   http://lfw.linuxhq.com/
   
   Also check out the Freshmeat Web site http://www.freshmeat.org,
   which is really cool. ("What online/free periodicals exist for
   Linux? "
   
   If you don't find anything, you could download the sources to the
   program yourself and compile them. See "How do I port XXX to
   Linux? " If it's a large package that may require some porting, pos
   a message to comp.os.linux.development.apps.
   
   If you compile a large-ish program, please upload it to one or more
   the FTP sites, and post a message to comp.os.linux.announce (submit
   your posting to linux-announce@news.ornl.gov).
   
   If you're looking for an application program, the chances are that
   someone has already written a free version. The comp.sources.wanted
   FAQ has instructions for finding the source code.
   
   
5.6 Can I use code or a compiler compiled for a 486 on my 386?

   Yes, unless it's the kernel.
   
   The -m486 option to GCC, which is used to compile binaries for x486
   machines, merely changes certain optimizations. This makes for
   slightly larger binaries that run somewhat faster on a 486. They st
   work fine on a 386, though, with a small performance hit.
   
   However, from version 1.3.35 the kernel uses 486 or Pentium-specifi
   instructions if configured for a 486 or Pentium, thus making it
   unusable on a 386.
   
   GCC can be configured for a 386 or 486; the only difference is that
   configuring it for a 386 makes -m386 the default and configuring fo
   486 makes -m486 the default. In either case, these can be overridde
   on a per-compilation basis or by editing
   /usr/lib/gcc-lib/i*-linux/n.n.n/specs.
   
   There is an Alpha version of GCC which knows how to do optimization
   well for the 586, but it is quite unreliable, especially at high
   optimization settings. The Pentium GCC can be found on tsx-11.mit.e
   in /pub/linux/ALPHA/pentium-gcc. I'd recommend using the ordinary 4
   GCC instead; word has it that using -m386 produces code that's bett
   for the Pentium, or at least slightly smaller.
   
   
5.7 What does gcc -O6 do?

   Currently, the same as -O2 (GCC 2.5) or -O3 (GCC 2.6, 2.7). Any num
   greater than that does the same thing. The Makefiles of newer kerne
   use -O2, and you should probably do the same.
   
   
5.8 Where are linux/*.h and asm/*.h?

   The files /usr/include/linux/ and /usr/include/asm/ are often soft
   links to the directories where the kernel headers are. They are
   usually under /usr/src/kernel*/.
   
   If you don't have the kernel sources, download them--see, "How
   do I upgrade/recompile my kernel? "
   
   Then, use rm to remove any garbage, and ln to create the links:
rm -rf /usr/include/linux /usr/include/asm
ln -sf /usr/src/linux/include/linux /usr/include/linux
ln -sf /usr/src/linux/include/asm /usr/include/asm

   /usr/src/linux/include/asm/ is a symbolic link to an
   architecture-specific asm directory--if you have a freshly unpacked
   kernel source tree, you must make symlinks. You'll also find that y
   may need to do `make config' in a newly-unpacked kernel source tree
   to create linux/autoconf.h.
   
   
5.9 I get errors when I try to compile the kernel.

   See the previous question regarding the header files.
   
   Remember that when you apply a patch to the kernel, you must use th
   -p0 or -p1 option: otherwise, the patch may be misapplied. See the
   patch manual page for details.
   
   "ld: unrecognized option `-qmagic"' means that you should get a
   newer linker, from ftp://tsx-11.mit.edu/pub/linux/packages/GCC/,
   in the file binutils-2.8.1.0.1.bin.tar.gz.
   
   
5.10 How do I make a shared library?

   For ELF,
   gcc -fPIC -c *.c
   gcc -shared -Wl,-soname,libfoo.so.1 -o libfoo.so.1.0 *.o

   For a.out, get tools-n.nn.tar.gz from tsx-11.mit.edu, in
   /pub/linux/packages/GCC/src/. It comes with documentation that will
   tell you what to do. Note that a.out shared libraries are a very
   tricky business. Consider upgrading your libraries to ELF shared
   libraries. See the ELF HOWTO, at
   sunsite.unc.edu/pub/Linux/docs/HOWTO/
   
   
5.11 My executables are (very) large.

   With an ELF compiler ("What's all this about ELF? "), the most
   common cause of large executables is the lack of an appropriate .so
   library link for one of the libraries you're using. There should be
   link like libc.so for every library like libc.so.5.2.18.
   
   With an a.out compiler the most common cause of large executables i
   the -g linker (compiler) flag. This produces (as well as debugging
   information in the output file) a program which is statically
   linked--one which includes a copy of the C library instead of a
   dynamically linked copy.
   
   Other things worth investigating are -O and -O2, which enable
   optimization (check the GCC documentation), and -s (or the strip
   command) which strip the symbol information from the resulting bina
   (making debugging totally impossible).
   
   You may wish to use -N on very small executables (less than 8K with
   the -N), but you shouldn't do this unless you understand its
   performance implications, and definitely never with daemons.
   
   
5.12 Does Linux support threads or lightweight processes?

   As well as the Unix multiprocessing model involving heavyweight
   processes, which is of course part of the standard Linux kernel, th
   are several implementations of lightweight processes or threads.
   Recent kernels implement a thread model, kthreads. In addition, the
   are the following packages available for Linux.
     * GNU glibc2 for Linux has optional support for threads. The arch
       is available from the same place as glibc2,
       ftp://ftp.gnu.org/pub/gnu
     * In sipb.mit.edu:/pub/pthread or
       ftp.ibp.fr:/pub/unix/threads/pthreads. Documentation isn't in t
       package, but is available on the World Wide Web at
       http://www.mit.edu:8001/people/proven/home_page.html. Newer Lin
       libc's contain the pthreads source. The GNU Ada compiler on
       sunsite.unc.edu in
       /pub/Linux/devel/lang/ada/gnat-3.01-linux+elf.tar.gz contains
       binaries made from that source code.
     * In ftp.cs.washington.edu:/pub/qt-001.tar.Z is QuickThreads. Mor
       information can be found in the technical report, available on 
       same site as /tr/1993/05/UW-CSE-93-05-06.PS.Z.
     * In gummo.doc.ic.ac.uk/rex/ is lwp, a very minimal implementatio
     * In ftp.cs.fsu.edu:/pub/PART/, an Ada implementation. This is
       useful mainly because it has a lot of Postscript papers that
       you'll find useful in learning more about threads. This is not
       directly usable under Linux.
       
   Please contact the authors of the packages in question for details.
   
   
5.13 Where can I get `lint' for Linux?

   Roughly equivalent functionality is built into GCC. Use the -Wall
   option to turn on most of the useful extra warnings. See the GCC
   manual for more details (type control-h followed by i in Emacs and
   select the entry for GCC).
   
   There is a freely available program called `lclint' that does much 
   same thing as traditional lint. The announcement and source code ar
   available at on larch.lcs.mit.edu in /pub/Larch/lclint/; on the Wor
   Wide Web, look at http://larch-www.lcs.mit.edu:8001/larch/lclint.ht
   
   
5.14 Where can I find kermit for Linux?

   Kermit is distributed under a non-GPL copyright that makes its term
   of distribution somewhat different. The sources and some binaries a
   available on kermit.columbia.edu.
   
   The WWW Home Page of the Columbia University Kermit project is
   http://www.columbia.edu/kermit/.
   
   
   contents
   
   
6. Solutions to common miscellaneous problems.

   
6.1 free dumps core.

   In Linux 1.3.57 and later, the format of /proc/meminfo was changed 
   a way that the implementation of free doesn't understand.
   
   Get the latest version, from sunsite.unc.edu, in
   /pub/Linux/system/Status/ps/procps-0.99.tgz.
   
   
6.2 My clock is very wrong.

   There are two clocks in your computer. The hardware (CMOS) clock ru
   even when the computer is turned off, and is used when the system
   starts up and by DOS (if you use DOS). The ordinary system time, sh
   and set by "date," is maintained by the kernel while Linux is
   running.
   
   You can display the CMOS clock time, or set either clock from the
   other, with /sbin/clock program--see "man 8 clock."
   
   There are various other programs that can correct either or both
   clocks for system drift or transfer time across the network. Some o
   them may already be installed on your system. Try looking for adjti
   (corrects for drift), netdate, and getdate (get the time from the
   network), or xntp (accurate, full-featured network time daemon).
   
   
6.3 Setuid scripts don't seem to work.

   That's right. This feature has been disabled in the Linux kernel on
   purpose, because setuid scripts are almost always a security hole.
   Sudo and SuidPerl can provide more security that setuid scripts or
   binaries, especially if execute permissions are limited to a certai
   user ID or group ID.
   
   If you want to know why setuid scripts are a security hole, read th
   FAQ for comp.unix.questions.
   
   
6.4 Free memory as reported by free keeps shrinking.

   The "free" figure printed by free doesn't include memory used as a
   disk buffer cache--shown in the "buffers" column. If you want to
   know how much memory is really free add the "buffers" amount to
   "free"--newer versions of free print an extra line with this info.
   
   The disk buffer cache tends to grow soon after starting Linux up. A
   you load more programs and use more files, the contents get cached.
   will stabilize after a while.
   
   
6.5 When I add more memory, the system slows to a crawl.

   This is a common symptom of a failure to cache the additional memor
   The exact problem depends on your motherboard.
   
   Sometimes you have to enable caching of certain regions in your BIO
   setup. Look in the CMOS setup and see if there is an option to cach
   the new memory area which is currently switched off. This is
   apparently most common on a '486.
   
   Sometimes the RAM has to be in certain sockets to be cached.
   
   Sometimes you have to set jumpers to enable caching.
   
   Some motherboards don't cache all of the RAM if you have more RAM p
   amount of cache than the hardware expects. Usually a full 256K cach
   will solve this problem.
   
   If in doubt, check the manual. If you still can't fix it because th
   documentation is inadequate, you might like to post a message to
   comp.os.linux.hardware giving all of the details--make, model numbe
   date code, etc., so other Linux users can avoid it.
   
   
6.6 Some programs (e.g. xdm) won't let me log in.

   You are probably using non-shadow password programs and are using
   shadow passwords.
   
   If so, you have to get or compile a shadow password version of the
   programs in question. The shadow password suite can be found at
   tsx-11.mit.edu:/pub/linux/sources/usr.bin/shadow/. This is the sour
   code. The binaries are probably in linux/binaries/usr.bin/.
   
   
6.7 Some programs let me log in with no password.

   You probably have the same problem as in "Some programs (e.g.
   xdm) won't let me log in. ", with an added wrinkle.
   
   If you are using shadow passwords, you should put a letter `x' or a
   asterisk in the password field of /etc/passwd for each account, so
   that if a program doesn't know about the shadow passwords it won't
   think it's a passwordless account and let anyone in.
   
   
6.8 My machine runs very slowly when I run GCC / X / ...

   You may have too little real memory. If you have less RAM than all 
   programs you're running at once, Linux will swap to your hard disk
   instead and thrash horribly. The solution in this case is to not ru
   so many things at once or buy more memory. You can also reclaim som
   memory by compiling and using a kernel with less options configured
   See "How do I upgrade/recompile my kernel? ".
   
   You can tell how much memory and swap you're using with the free
   command, or by typing:
cat /proc/meminfo

   If your kernel is configured with a RAM disk, this is probably wast
   space and will cause things to go slowly. Use LILO or rdev to tell 
   kernel not to allocate a RAM disk (see the LILO documentation or ty
   man rdev).
   
   
6.9 I can only log in as root.

   You probably have some permission problems, or you have a file
   /etc/nologin.
   
   In the latter case, put rm -f /etc/nologin in your /etc/rc.local or
   /etc/rc.d/* scripts.
   
   Otherwise, check the permissions on your shell, and any file names
   that appear in error messages, and also the directories that contai
   these files, up to and including the root directory.
   
   
6.10 My screen is all full of weird characters instead of letters.

   You probably sent some binary data to your screen by mistake. Type
   echo '\033c' to fix it. Many Linux distributions have a command,
   "reset," that does this.
   
   If that doesn't help, try a direct screen escape command.
echo <Ctrl-V><Ctrl-O>

   This resets the default font of a Linux console. Remember to hold d
   the Control key and type the letter, instead of, for example,
   `Ctrl-V'. The sequence
echo <Ctrl-V><Esc>c

   causes a full screen reset. If there's data left on the shell comma
   line after typing a binary file, press Ctrl-C a few times to restor
   the shell command line.
   
   [Bernhard Gabler]
   
   
6.11 I have screwed up my system and can't log in to fix it.

   Reboot from an emergency floppy or floppy pair. For example, the
   Slackware boot and root disk pair in the install subdirectory of th
   Slackware distribution.
   
   There are also two, do-it-yourself rescue disk creation packages in
   sunsite.unc.edu/pub/Linux/system/Recovery. These are better
   because they have your own kernel on them, so you don't run the ris
   of missing devices and file systems.
   
   Get to a shell prompt and mount your hard disk with something like
mount -t ext2 /dev/hda1 /mnt

   Then your file system is available under the directory /mnt and you
   can fix the problem. Remember to unmount your hard disk before
   rebooting (cd somewhere else first, or it will say it's busy).
   
   
6.12 I've discovered a huge security hole in rm!

   No you haven't. You are obviously new to Unix and need to read a go
   book to find out how things work. Clue: the ability to delete files
   under Unix depends on permission to write in that directory.
   
   
6.13 lpr(1) and/or lpd(8) don't work.

   First make sure that your /dev/lp* port is correctly configured. It
   IRQ (if any) and port address need to match the settings on the
   printer card. You should be able to dump a file directly to the
   printer.
cat the_file >/dev/lp1

   If lpr gives you a message like "myname@host: host not found," it
   may mean that the TCP/IP loopback interface, lo, isn't working
   properly. Loopback support is compiled into most distribution kerne
   Check that the interface is configured with the ifconfig command. B
   Internet convention, the network number is 127.0.0.0, and the local
   host address is 127.0.0.1. If everything is configured correctly, y
   should be able to telnet to your own machine and get a login prompt
   
   Make sure that /etc/hosts.lpd contains the machine's host name.
   
   If your machine has a network-aware lpd, like the one that comes wi
   LPRng, make sure that /etc/lpd.perms is configured correctly.
   
   Also look at the Printing-HOWTO "Where can I get the HOWTO's
   and other documentation? ".
   
   
6.14 Timestamps on files on MS-DOS partitions are set incorrectly.

   There is a bug in the program "clock" (often found in /sbin). It
   miscounts a time zone offset, confusing seconds with minutes or
   something like that. Get a recent version.
   
   
6.15 How do I get LILO to boot the vmlinux file?

   >From kernel versions 1.1.80 on, the compressed kernel image, which
   what LILO needs to find, is in arch/i386/boot/zImage. The vmlinux f
   in the root directory is the uncompressed kernel, and you shouldn't
   try to boot it.
   
   This was changed to make it easier to build kernel versions for
   several different processors from one source tree.
   
   
   contents
   
   
7. How do I do this or find out that ... ?

   
7.1 How can I get scrollback in text mode?

   With the default US keymap, you can use Shift with the PageUp and
   PageDown keys. (The gray ones, not the ones on the numeric keypad.)
   With other keymaps, look in /usr/lib/keytables. You can remap the
   ScrollUp and ScrollDown keys to be whatever you like. For example, 
   remap them to the keys on an 84-key, AT keyboard.
   
   The "screen" program,
   http://vector.co.jp/vpack/browse/person/an010455.html provides a
   searchable scrollback buffer and the ability to take "snapshots" of
   text-mode screens.
   
   You can't increase the amount of scrollback, because it is implemen
   using the video memory to store the scrollback text. You may be abl
   to get more scrollback in each virtual console by reducing the tota
   number of VC's. See linux/tty.h.
   
   
7.2 How do I switch virtual consoles? How do I enable them?

   In text mode, press Left Alt-F1 to Alt-F12 to select the consoles t
   to tty12; Right Alt-F1 gives tty13 and so on. To switch out of X
   Windows you must press Ctrl-Alt-F1, etc; Alt-F5 or whatever will
   switch back.
   
   If you want to use a VC for ordinary login, it must be listed in
   /etc/inittab, which controls which terminals and virtual consoles h
   login prompts. The X Window System needs at least one free VC in or
   to start.
   
   
7.3 How do I set the time zone?

   Change directory to /usr/lib/zoneinfo/. Get the time zone package i
   you don't have this directory. The source is available as
   sunsite.unc.edu/pub/Linux/system/admin/time/timesrc-1.2.tar.gz.
   
   Then make a symbolic link named localtime pointing to one of the fi
   in this directory (or a subdirectory), and one called posixrules
   pointing to localtime. For example:
   ln -sf US/Mountain localtime
   ln -sf localtime posixrules

   This change will take effect immediately--try date(1).
   
   The manual page for tzset describes setting the time zone. Some
   programs recognize the TZ environment variable, but this is not
   POSIX-correct.
   
   You should also make sure that your Linux kernel clock is set to th
   correct GMT time--type date -u and check that the correct UTC time 
   displayed. ("My clock is very wrong. ")
   
   
7.4 What version of Linux and what machine name am I using?

   Type:
uname -a

   
7.5 How can I enable or disable core dumps?

   By using the ulimit command in bash, the limit command in tcsh, or 
   rlimit command in ksh. See the appropriate manual page for details.
   
   This setting affects all programs run from the shell (directly or
   indirectly), not the whole system.
   
   If you wish to enable or disable core dumping for all processes by
   default, you can change the default setting in linux/sched.h--see t
   definition of INIT_TASK, and look also in linux/resource.h.
   
   
7.6 How do I upgrade/recompile my kernel?

   See the Kernel HOWTO or the README files which come with the kernel
   release on ftp.cs.helsinki.fi, in /pub/Software/Linux/Kernel/ and
   mirrors. (See "Where can I get Linux material by FTP? ") You
   may already have a version of the kernel source code installed on y
   system, but if it is part of a standard distribution it is likely t
   be somewhat out of date (this is not a problem if you only want a
   custom configured kernel, but it probably is if you need to upgrade
   
   With newer kernels you can (and should) make all of the following
   targets. Don't forget that you can specify multiple targets with on
   command.
make clean dep install modules modules_install

   Also remember to update the module dependencies.
depmod -a

   Remember that to make the new kernel boot you must run LILO after
   copying the kernel into your root partition--the Makefile in recent
   kernels has a special zlilo target for this; try:
make zlilo

   Kernel version numbers with an odd minor version (ie, 1.1.x, 1.3.x)
   are the testing releases; stable production kernels have even minor
   versions (1.0.x, 1.2.x). If you want to try the testing kernels you
   should probably subscribe to the linux-kernel mailing list. (See "
   What mailing lists are there? .")
   
   
7.7 Can I have more than 3 serial ports by sharing interrupts?

   Yes, but you won't be able to use simultaneously two ordinary ports
   which share an interrupt (without some trickery). This is a limitat
   of the ISA Bus architecture.
   
   See the Serial HOWTO for information about possible solutions and
   workarounds for this problem.
   
   
7.8 How do I make a bootable floppy?

   Make a file system on it with bin, etc, lib and dev
   directories--everything you need. Install a kernel on it and arrang
   to have LILO boot it from the floppy (see the LILO documentation, i
   lilo.u.*.ps).
   
   If you build the kernel (or tell LILO to tell the kernel) to have a
   RAM disk the same size as the floppy the RAM disk will be loaded at
   boot time and mounted as root in place of the floppy.
   
   See the Bootdisk HOWTO.
   
   
7.9 How do I remap my keyboard to UK, French, etc.?

   For recent kernels, get /pub/Linux/system/Keyboards/kbd-0.90.tar.gz
   from sunsite.unc.edu. Make sure you get the appropriate version; yo
   have to use the right keyboard mapping package for your kernel
   version.
   
   For older kernels you have to edit the top-level kernel Makefile, i
   /usr/src/linux.
   
   You may find more helpful information in The Linux Keyboard and
   Console HOWTO, by Andries Brouwer, at
   sunsite.unc.edu/pub/Linux/docs/HOWTO.
   
   
7.10 How do I get NUM LOCK to default to on?

   Use the setleds program, for example (in /etc/rc.local or one of th
   /etc/rc.d/* files):
for t in 1 2 3 4 5 6 7 8
do
    setleds +num < /dev/tty$t > /dev/null
done

   Setleds is part of the kbd package ("How do I remap my keyboard
   to UK, French, etc.? ").
   
   Alternatively, patch your kernel. You need to arrange for KBD_DEFLE
   to be defined to (1 << VC_NUMLOCK) when compiling
   drivers/char/keyboard.c.
   
   
7.11 How do I set (or reset) my initial terminal colors?

   The following shell script should work for VGA consoles:
for n in 1 2 4 5 6 7 8; do
        setterm -fore yellow -bold on -back blue -store > /dev/tty$n
        done

   Substitute your favorite colors, and use /dev/ttyS$n for serial
   terminals.
   
   To make sure they are reset when people log out (if they've been
   changed):
   
   Replace the references to "getty" (or "mingetty" or "uugetty" or
   whatever) in /etc/inittab with references to "/sbin/mygetty."
#!/bin/sh
setterm -fore yellow -bold on -back blue -store > $1
exec /sbin/mingetty $@

   [Jim Dennis]
   
7.12 How can I have more than 128Mb of swap?

   Use several swap partitions or swap files--Linux supports up to 16
   swap areas, each of up to 128Mb.
   
   Very old kernels only supported swap partition sizes up to 16Mb.
   
   Linux on machines with 8KB paging, like Alpha and Sparc64, support 
   swap partition up to 512KB. The 128KB limitation comes from
   PAGE_SIZE*BITSPERBYTE on machines with 4KB paging, but is 512KB on
   machines with 8KB paging. The limit is due to the use of a single p
   allocation map.
   
   The file mm/swapfile.c has all of the gory details.
   
   [Peter Moulder, Gordon Weast]
   
   
   contents
   
   
8. Miscellaneous information and questions answered.

   
8.1 How do I program XYZ under Linux?

   Read the manuals, or a good book on Unix. Manual pages (type "man
   man") are usually a good source of reference information on exactly
   how to use a particular command or function.
   
   There is also a lot of GNU Info documentation, which is often more
   useful as a tutorial. Run Emacs and type C-h i, or type info info i
   you don't have or don't like Emacs. Note that the Emacs libc node m
   not exactly describe the latest Linux libc, or GNU glibc2. But the 
   progject and LDP are always looking for volunteers to upgrade their
   library documentation.
   
   Anyway, between the existing Texinfo documentation, and the manual
   pages in sections 2 and 3, should provide enough information to get
   started.
   
   As with all free software, the best tutorial is the source code
   itself.
   
   The latest release of the Linux manual pages, a collection of usefu
   GNU Info documentation, and various other information related to
   programming Linux, can be found on sunsite.unc.edu in
   /pub/Linux/docs/man-pages.
   
   
8.2 What's all this about ELF?

   See the ELF HOWTO by Daniel Barlow--note, this is not the file
   move-to-elf, which is a blow-by-blow account of how to upgrade to E
   manually.
   
   Linux has two different formats for executables, object files, and
   object code libraries, known as, "ELF." (The old format is called
   `a.out'.) They have advantages, including better support for shared
   libraries and dynamic linking.
   
   Both a.out and ELF binaries can coexist on a system. However, they 
   different shared C libraries, both of which have to be installed.
   
   If you want to find out whether your system can run ELF binaries, l
   in /lib for a file named, "libc.so.5." If it's there, you probably
   have ELF libraries. If you want to know whether your installation
   actually is ELF you can pick a representative program, like ls, and
   run file on it:
-chiark:~> file /bin/ls
/bin/ls: Linux/i386 impure executable (OMAGIC) - stripped

valour:~> file /bin/ls
/bin/ls: ELF 32-bit LSB executable, Intel 80386, version 1, stripped

   There is a patch to get 1.2.x to compile using the ELF compilers, a
   produce ELF core dumps, at tsx-11.mit.edu in /pub/packages/GCC/. Yo
   do not need the patch merely to run ELF binaries. 1.3.x and later d
   not need the patch at all.
   
   
8.3 What is a .gz file ? And a .tgz ? And ... ?

   .gz (and .z) files are compressed using GNU gzip. You need to use
   gunzip (which is a symlink to the gzip command which comes with mos
   Linux installations) to unpack the file.
   
   .taz and .tz are tar files (made with Unix tar) compressed using
   standard Unix compress.
   
   .tgz (or .tpz) is a tar file compressed with gzip.
   
   .lsm is a Linux Software Map entry, in the form of a short text fil
   Details about the LSM and the LSM itself are available in the docs
   subdirectory on sunsite.unc.edu.
   
   .deb is a Debian Binary Package - the binary package format used by
   the Debian GNU/Linux distribution. It is manipulated using dpkg and
   dpkg-deb (available on Debian systems and from ftp.debian.org).
   
   .rpm is a Red Hat RPM package, which is used in the Red Hat
   distribution. They can be found on ftp.redhat.com.
   
   .bz2 is a file compressed by the more recent bzip program.
   
   The "file" command can often tell you what a file is.
   
   If you find that gzip complains when you try to uncompress a gzip'e
   file you probably downloaded it in ASCII mode by mistake. You must
   download most things in binary mode--remember to type binary as a
   command in FTP before using, "get," to get the file.
   
   
8.4 What does VFS stand for?

   Virtual File System. It's the abstraction layer between the user an
   real file systems like ext2, Minix and MS-DOS. Among other things, 
   job is to flush the read buffer when it detects a disk change on th
   floppy disk drive.
VFS: Disk change detected on device 2/0

   
8.5 What is a BogoMip?

   "BogoMips" is a contraction of "Bogus MIPS." MIPS stands for
   (depending who you listen to) Millions of Instructions per Second, 
   Meaningless Indication of Processor Speed.
   
   The number printed at boot time is the result of a kernel timing
   calibration, used for very short delay loops by some device drivers
   
   As a very rough guide, the BogoMips rating for your machine will be
   approximately:
     386SX              clock * 0.14
     386DX              clock * 0.18
     486Cyrix/IBM       clock * 0.33
     486SX/DX/DX2       clock * 0.50
     586                clock * 0.39

   If the number is wildly lower, you may have the Turbo button or CPU
   speed set incorrectly, or have some kind of caching problem (as
   described in "When I add more memory, the system slows to a
   crawl. .")
   
   For values people have seen with other, rarer, chips, see the BogoM
   Mini-HOWTO, on sunsite.unc.edu in
   /pub/Linux/docs/howto/mini/BogoMips/.
   
   
8.6 What is the Linux Journal and where can I get it?

   The Linux Journal is a monthly magazine (printed on paper) that is
   available on news stands and via subscription worldwide. Email
   linux@ssc.com for details. Their URL is http://www.ssc.com/.
   
   
8.7 What online/free periodicals exist for Linux?

   There are a number of recent additions to the list of periodicals
   devoted to Linux.
     * Linux Gazette. http://www.linuxgazette.com.
     * Linux Weekly News. http://www.lwn.net.
     * Slashdot. http://www.slashdot.org.
     * Freshmeat. http://www.freshmeat.org.
       
   [Jim Dennis, Robert Kiesling]
   
   
8.8 How many people use Linux?

   Linux is freely available, and no one is required to register their
   copy with any central authority, so it is difficult to know. Severa
   businesses survive solely on selling and supporting Linux. The Linu
   newsgroups are some of the most heavily read on Usenet, so the numb
   is likely in the hundreds of thousands. Accurate numbers probably
   don't exist.
   
   However, one brave soul, Harald T. Alvestrand,
   Harald.T.Alvestrand@uninett.no, has decided to try, and asks that
   if you use Linux, send a message to linux-counter@uninett.no with
   one of the following subjects: "I use Linux at home," "I use Linux
   at work," or, "I use Linux at home and at work." He will also
   accept `third party' registrations--ask him for details.
   
   Alternatively, you can register using the WWW forms found at
   http://domen.uninett.no/~hta/linux/counter.html.
   
   He posts his counts to aun.uninett.no in /pub/misc/linux-counter/ o
   at the web page above.
   
   
8.9 How should I pronounce Linux?

   This is a matter of religious debate, of course!
   
   If you want to hear Linus himself say how he pronounces it, downloa
   english.au or swedish.au from ftp.funet.fi (in
   /pub/Linux/PEOPLE/Linus/SillySounds/). If you have a sound card or 
   PC-speaker audio driver you can hear them by typing
cat english.au >/dev/audio

   The difference isn't in the pronunciation of Linux but in the langu
   Linus uses to say, "hello."
   
   For the benefit of those who don't have the equipment or inclinatio
   Linus pronounces Linux approximately as Leenus, where the "ee" is
   pronounced as in "feet," but rather shorter, and the "u" is like a
   much shorter version of the French "eu" sound in "peur"
   (pronouncing it as the "u" in "put" is probably passable).
   
   
   contents
   
   
9. Frequently encountered error messages.

   
9.1 Modprobe can't locate module, "XXX," and similar messages.

   These types of messages mostly occur at boot time or shutdown. If
   modprobe, insmod, or rmmod complain about not being able to find a
   module, add the following to the /etc/modules.conf or
   /etc/modutils/aliases file, whichever is present on your system.
alias <module-name> off

   And use the name of the module that appears in the error message.
   
   [J.H.M. Dassen]
   
   
9.2 Unknown terminal type linux and similar.

   In early kernels the default console terminal type has changed from
   "console" to "linux." You must edit /etc/termcap to change the
   line reading:
console|con80x25:\

   to
linux|console|con80x25:\

   (there may be an additional dumb in there--if so it should be
   removed.)
   
   To get the editor to work you may need say
TERM=console

   (for bash and ksh), or
setenv TERM console

   for csh or tcsh.
   
   Some programs use /usr/lib/terminfo instead of /etc/termcap. For th
   programs you should upgrade your terminfo, which is part of ncurses
   
   
9.3 lp1 on fire

   This is a joke/traditional error message indicating that some sort 
   error is being reported by your printer, but that the error status
   isn't a valid one. It may be that you have some kind of I/O or IRQ
   conflict-- check your cards' settings. Some people report that they
   get this message when their printer is switched off. Hopefully it
   isn't really on fire ...
   
   In newer kernels, this message reads, "lp1 reported invalid error
   status (on fire, eh?)"
   
   
9.4 INET: Warning: old style ioctl... called!

   You are trying to use the old network configuration utilities. The 
   ones can be found on ftp.linux.org.uk in
   /pub/linux/Networking/PROGRAMS/NetTools/ (source only, I'm afraid).
   
   Note that they cannot be used just like the old-style programs. See
   the NET-2 HOWTO for instructions on how to set up the old-style
   networking programs correctly. Even better, see the NET-3 HOWTO and
   upgrade your networking software.
   
   
9.5 ld: unrecognized option '-m486'

   You have an old version of ld. Install a newer binutils package--th
   will contain an updated ld. Look on tsx-11.mit.edu in
   /pub/linux/packages/GCC/ for binutils-2.6.0.2.bin.tar.gz.
   
   
9.6 GCC says Internal compiler error.

   If the fault is repeatable (i.e., it always happens at the same pla
   in the same file--even after rebooting and trying again, using a
   stable kernel) you have discovered a bug in GCC. See the GCC Info
   documentation (type Control-h i in Emacs, and select GCC from the
   menu) for details on how to report the error--make sure you have th
   latest version, though.
   
   Note that this is probably not a Linux-specific problem. Unless you
   are compiling a program many other Linux users also compile, you
   should not post your bug report to any of the comp.os.linux groups.
   
   If the problem is not repeatable, you may be experiencing memory
   corruption--see make says Error 139 .
   
   
9.7 make says Error 139

   Your compiler driver (gcc) dumped core. You probably have a corrupt
   buggy, or old version of GCC--get the latest release. Alternatively
   you may be running out of swap space--see My machine runs very
   slowly when I run GCC / X / ... .
   
   If this doesn't fix the problem, you are probably having problems w
   memory or disk corruption. Check that the clock rate, wait states, 
   refresh timing for your SIMMS and cache are correct (hardware manua
   are sometimes wrong, too). If so, you may have some marginal SIMMS,
   a faulty motherboard or hard disk or controller.
   
   Linux, like any Unix, is a very good memory tester--much better tha
   MS-DOS based memory test programs.
   
   Reportedly, some clone x87 math coprocessors can cause problems. Tr
   compiling a kernel with math emulation ( How do I
   upgrade/recompile my kernel? .) You may need to use the "no387"
   kernel command line flag on the LILO prompt to force the kernel to 
   math emulation, or it may be able to work and still use the '387, w
   the math emulation compiled in but mainly unused.
   
   More information about this problem is available on the Web at
   http://www.bitwizard.nl/sig11/.
   
   
9.8 shell-init: permission denied when I log in.

   Your root directory and all the directories up to your home directo
   must be readable and executable by everybody. See the manual page f
   chmod or a book on Unix for how to fix the problem.
   
   
9.9 No utmp entry. You must exec ... when I log in.

   Your /var/run/utmp is screwed up. You should have
> /var/run/utmp

   in your /etc/rc.local or /etc/rc.d/*. See ("I have screwed up
   my system and can't log in to fix it. ") Note that the utmp may als
   be found in /var/adm/ or /etc/ on some older systems.
   
   
9.10 Warning--bdflush not running.

   Modern kernels use a better strategy for writing cached disk blocks
   In addition to the kernel changes, this involves replacing the old
   update program which used to write everything every 30 seconds with
   more subtle daemon (actually a pair), known as bdflush.
   
   Get bdflush-n.n.tar.gz from the same place as the kernel source cod
   How do I upgrade/recompile my kernel? ) and compile and install
   it. Bdflush should be started before the usual boot-time file syste
   checks. It will work fine with older kernels as well, so there's no
   need to keep the old update around.
   
   
9.11 Warning: obsolete routing request made.

   This is nothing to worry about. The message means that your version
   route is a little out of date, compared to the kernel. You can make
   the message go away by getting a new version of route from the same
   place as the kernel source code. ( How do I upgrade/recompile my
   kernel? )
   
   
9.12 EXT2-fs: warning: mounting unchecked file system.

   You need to run e2fsck (or fsck -t ext2 if you have the fsck front 
   program) with the -a option to get it to clear the `dirty' flag, an
   then cleanly unmount the partition during each shutdown.
   
   The easiest way to do this is to get the latest fsck, umount, and
   shutdown commands, available in Rik Faith's util-linux package (`
   Where can I get Linux material by FTP? ") You have to make sure
   that your /etc/rc*/ scripts use them correctly.
   
   NB: don't try to check a file system that's mounted read/write--thi
   includes the root partition if you don't see
VFS: mounted root ... read-only

   at boot time. You must arrange to mount the root file system read/o
   to start with, check it if necessary, and then remount it read/writ
   Read the documentation that comes with util-linux to find out how t
   do this.
   
   Note that you need to specify the -n option to mount so it won't tr
   to update /etc/mtab, since the root file system is still read-only,
   and this will otherwise cause it to fail.
   
   
9.13 EXT2-fs warning: maximal count reached.

   This message is issued by the kernel when it mounts a file system
   that's marked as clean, but whose "number of mounts since check"
   counter has reached the predefined value. The solution is to get th
   latest version of the ext2fs utilities (e2fsprogs-0.5b.tar.gz at th
   time of writing) from the usual sites. (` Where can I get Linux
   material by FTP? ")
   
   The maximal number of mounts value can be examined and changed usin
   the tune2fs program from this package.
   
   
9.14 EXT2-fs warning: checktime reached.

   Kernels from 1.0 onwards support checking a file system based on th
   elapsed time since the last check as well as by the number of mount
   Get the latest version of the ext2fs utilities. "( EXT2-fs
   warning: maximal count reached. ")
   
   
9.15 df says Cannot read table of mounted file systems.

   There is probably something wrong with your /etc/mtab or /etc/fstab
   files. If you have a reasonably new version of mount, /etc/mtab sho
   be emptied or deleted at boot time (in /etc/rc.local or /etc/rc.d/*
   using something like
rm -f /etc/mtab*

   Some versions of SLS have an entry for the root partition in /etc/m
   made in /etc/rc* by using rdev. This is incorrect--the newer versio
   of mount do this automatically.
   
   Other versions of SLS have a line in /etc/fstab that looks like:
/dev/sdb1   /root   ext2   defaults

   This is wrong. /root should read simply /.
   
   
9.16 fdisk says Partition X has different physical/logical ...

   If the partition number (X, above) is 1, this is the same problem a
   in "fdisk: Partition 1 does not start on cylinder boundary. "
   
   If the partition begins or ends on a cylinder numbered greater than
   1024, this is because the standard DOS disk geometry information
   format in the partition table can't cope with cylinder numbers with
   more than 10 bits. You should see "How can I get Linux to work
   with my disk? "
   
   
9.17 fdisk: Partition 1 does not start on cylinder boundary.

   The version of fdisk that comes with many Linux systems creates
   partitions that fail its own validity checking. Unfortunately, if
   you've already installed your system, there's not much you can do
   about this, apart from copying the data off the partition, deleting
   and remaking it, and copying the data back.
   
   You can avoid the problem by getting the latest version of fdisk, f
   Rik Faith's util-linux package (available on all the usual FTP site
   Alternatively, if you are creating a new partition 1 that starts in
   the first cylinder, you can do the following to get a partition tha
   fdisk likes.
     * Create partition 1 in the normal way. A `p' listing will produc
       the mismatch complaint.
     * Type `u' to set sector mode and do `p' again. Copy down the num
       from the "End" column.
     * Delete partition 1.
     * While still in sector mode, re-create partition 1. Set the firs
       sector to match the number of sectors per track. This is the
       sector number in the first line of the `p' output. Set the last
       sector to the value you wrote down in the step above.
     * Type `u' to reset cylinder mode and continue with other
       partitions.
       
   Ignore the message about unallocated sectors--they refer to the
   sectors on the first track apart from the Master Boot Record, and t
   are not used if you start the first partition in track 2.
   
   
9.18 fdisk says partition n has an odd number of sectors.

   The PC disk partitioning scheme works in 512-byte sectors, but Linu
   uses 1K blocks. If you have a partition with an odd number of secto
   the last sector is wasted. Ignore the message.
   
   
9.19 mtools says cannot initialize drive XYZ

   This means that mtools is having trouble accessing the drive. This 
   be due to several things.
   
   Often this is due to the permissions on floppy drive devices
   (/dev/fd0* and /dev/fd1*) being incorrect--the user running mtools
   must have the appropriate access. See the manual page for chmod for
   details.
   
   Most versions of mtools distributed with Linux systems (not the
   standard GNU version) use the contents of a file /etc/mtools to
   determine which devices and densities to use, in place of having th
   information compiled into the binary. Mistakes in this file often
   cause problems. There is often no documentation about this.
   
   For the easiest way to access your MS-DOS files (especially those o
   hard disk partition) see How do I access files on my DOS
   partition or floppy? Note--you should never use mtools to access fi
   on an msdosfs mounted partition or disk!
   
   
9.20 At the start of booting: Memory tight

   This means that you have an extra-large kernel, which means that Li
   has to do some special memory-management magic to be able to boot
   itself from the BIOS. It isn't related to the amount of physical
   memory in your machine. Ignore the message, or compile a kernel
   containing only the drivers and features you need. ("How do I
   upgrade/recompile my kernel? )"
   
   
9.21 My syslog says `end_request: I/O error, ...'.

   This error message, and messages like it, almost always indicate a
   hardware error with a hard drive.
   
   This commonly indicates a hard drive defect. The only way to avoid
   further data loss is to completely shut own the system. You must al
   make sure that whatever data is on the drive is backed up, and rest
   it to a non-defective hard drive.
   
   This error message may also indicate a bad connection to the drive,
   especially with homebrew systems. If you install an IDE drive, ALWA
   use new cables. It's probably is a good idea with SCSI drives, too.
   
   In one instance, this error also seemed to coincide with a bad grou
   between the system board and the chassis. Be sure that all electric
   connections are clean and tight before placing the blame on the har
   drive itself.
   
   [Peter Moulder, Theodore T'so]
   
   
9.22 You don't exist. Go away.

   This is not a viral infection :-). It comes from programs like writ
   talk, and wall, if your invoking UID doesn't correspond to a valid
   user (probably due to /etc/passwd being corrupted), or if the sessi
   (pseudoterminal, specifically) you're using isn't properly register
   in the utmp file (probably because you invoked it in a funny way).
   
   
   contents
   
   
10. The X Window System.

   
10.1 Does Linux support X Windows?

   Yes. Linux uses XFree86 (the current version is 3.3.2, which is bas
   on X11R6). You need to have a video card which is supported by
   XFree86. See the Linux XFree86 HOWTO for more details.
   
   Most Linux distributions nowadays come with an X installation.
   
   However, you can install or upgrade your own, from
   /pub/Linux/X11/Xfree86-* on sunsite.unc.edu and its mirror sites.
   
   
10.2 Where can I get an XF86Config for my system?

   See the Linux XFree86 HOWTO, recent versions of Installation and
   Getting Started, and the instructions for the XF86Setup program.
   
   The contents of the XF86Config file depend on the your exact
   combination of video card and monitor. It can either be configured 
   hand, or using the XF86Setup utility. Read the instructions that ca
   with XFree86, in /usr/X11R6/lib/X11/etc. The file you probably need
   look at most is README.Config.
   
   You should not use the sample XF86Config.eg file which is included
   with newer versions of XFree86 verbatim, because the wrong video cl
   settings can damage your monitor.
   
   Please don't post to comp.os.linux.x asking for an XF86Config, and
   please don't answer such requests.
   
   
10.3 xterm logins show up strangely in who, finger.

   The xterm that comes with XFree86 2.1 and earlier doesn't correctly
   understand the format that Linux uses for the /var/adm/utmp file,
   where the system records who is logged in. It therefore doesn't set
   all the information correctly.
   
   The Xterms in XFree86 3.1 and later versions fix this problem.
   
   
10.4 I can't get X Windows to work right.

   Read the XFree86 HOWTO--note the question and answer section.
   
   Try reading comp.windows.x.i386unix--specifically read the the FAQ 
   that group.
   
   Please don't post X Windows or XFree86 related questions to
   comp.os.linux.x unless they are Linux-specific.
   
   
   contents
   
   
11. Questions applicable to very out-of-date software.

   The questions in this section are only relevant to users of softwar
   that is at least three months old.
   
   Please let me know if you find the answer to a problem you had here
   as unused questions in this section will eventually disappear. (See
   Feedback is invited. ")
   
   
11.1 fdisk says cannot use nnn sectors of this partition.

   Originally Linux only supported the Minix file system, which cannot
   use more than 64Mb per partition. This limitation is not present in
   the more advanced file systems that are now available, such as ext2
   (the 2nd version of the Extended File System, the `standard' Linux
   file system).
   
   If you intend to use ext2fs you can ignore the message.
   
   
11.2 GCC sometimes uses huge amounts of virtual memory and thrashes.

   Older versions of GCC had a bug which made them use lots of memory 
   you tried to compile a program which had a large static data table 
   it.
   
   You can either upgrade your version of GCC, or add more swap space 
   necessary, or just wait for the program to finish compiling.
   
   
   contents
   
   
12. How to get further assistance.

   
12.1 You still haven't answered my question!

   Please read all of this answer before posting. I know it's a bit lo
   but you may be about to make a fool of yourself in front of 50,000
   people and waste hundreds of hours of their time. Don't you think i
   worth spending some of your time to read and follow these
   instructions?
   
   If you think an answer is incomplete or inaccurate, please e-mail
   Robert Kiesling at kiesling@terracom.net.
   
   Read the appropriate Linux Documentation Project books--see "
   Where can I get the HOWTO's and other documentation? "
   
   If you're a Unix newbie, read the FAQ for comp.unix.questions, and
   those for any of the other comp.unix.* groups that may be relevant.
   
   Linux has so much in common with commercial Unices, that almost
   everything you read there will apply to Linux. The FAQs, like all
   FAQs, be found on rtfm.mit.edu in /pub/usenet/news.answers (the
   mail-server@rtfm.mit.edu can send you these files, if you don't
   have FTP access). There are mirrors of rtfm's FAQ archives on vario
   sites--check the Introduction to *.answers posting, posted, or look
   news-answers/introduction in the directory above.
   
   Check the relevant HOWTO for the subject in question, if there is o
   or an appropriate old style sub-FAQ document. Check the FTP sites.
   
   Try experimenting--that's the best way to get to know Unix and Linu
   
   Read the documentation. Check the manual pages (type "man man" if
   you don't know about manual pages. Try "man -k subject"--it often
   lists useful and relevant manual pages.
   
   Check the Info documentation (type C-h i, i.e. Control H followed b
   in Emacs). This isn't just for Emacs. For example, the GCC
   documentation lives here as well.
   
   There will also often be a README file with a package that gives
   installation and/or usage instructions.
   
   Make sure you don't have a corrupted or out-of-date copy of the
   program in question. If possible, download it again and re-install
   it--you probably made a mistake the first time.
   
   Read comp.os.linux.announce--this often contains very important
   information for all Linux users.
   
   General X Window System questions belong in comp.windows.x.i386unix
   not in comp.os.linux.x. But read the group first (including the FAQ
   before you post.
   
   Only if you have done all of these things and are still stuck, shou
   you post to the appropriate comp.os.linux.* newsgroup. Make sure yo
   read the next question first. "( What to put in a request for
   help. )"
   
   
12.2 What to put in a request for help.

   Please read the following advice carefully about how to write your
   posting or email. Making a complete posting will greatly increase t
   chances that an expert or fellow user reading it will have enough
   information and motivation to reply.
   
   This advice applies both to postings asking for advice and to perso
   email sent to experts and fellow users.
   
   Make sure you give full details of the problem, including:
     * What program, exactly, you are having problems with. Include th
       version number if known and say where you got it. Many standard
       commands tell you their version number if you give them a
       --version option.
     * Which Linux release you're using (Red Hat, Slackware, Debian, o
       whatever) and what version of that release.
     * The exact and complete text of any error messages printed.
     * Exactly what behavior you expected, and exactly what behavior y
       observed. A transcript of an example session is a good way to s
       this.
     * The contents of any configuration files used by the program in
       question and any related programs.
     * What version of the kernel and shared libraries you have
       installed. The kernel version can be found by typing uname -a, 
       the shared library version by typing ls -l /lib/libc.so.4.
     * Details of what hardware you're running on, if it seems
       appropriate.
       
   You are in little danger of making your posting too long unless you
   include large chunks of source code or uuencoded files, so err on t
   side of giving too much information.
   
   Use a clear, detailed Subject line. Don't put things like `doesn't
   work', `Linux', `help', or `question' in it--we already know that.
   Save the space for the name of the program, a fragment of an error
   message, or summary of the unusual behavior.
   
   If you report an `unable to handle kernel paging request' message,
   follow the instructions in the Linux kernel sources README file for
   turning the numbers into something more meaningful. If you don't do
   this, no one who reads your post will be able to do it for you. The
   mapping from numbers to function names varies from one kernel to
   another.
   
   Put a summary paragraph at the top of your posting.
   
   At the bottom of your posting, ask for responses by email and say
   you'll post a summary. Back this up by using Followup-To: poster.
   Then, actually post the summary in a few days or a week or so. Don'
   just concatenate the replies you got--summarize. Putting the word
   SUMMARY in your summary's Subject line is also a good idea. Conside
   submitting the summary to comp.os.linux.announce.
   
   Make sure your posting doesn't have an inappropriate References:
   header line. This marks your article as part of the thread of the
   article referred to, which will often cause it to be junked by
   readers, along with the rest of a boring thread.
   
   You might like to say in your posting that you've read this FAQ and
   the appropriate HOWTO's--this may make people less likely to skip y
   posting.
   
   Remember that you should not post email sent to you personally with
   the sender's permission.
   
   
12.3 I want to mail someone about my problem.

   Try to find the author or developer of whatever program or componen
   is causing you difficulty. If you have a contact point for your Lin
   distribution, you should use it.
   
   Please put everything in your e-mail message that you would put in 
   posting asking for help.
   
   Finally, remember that, despite the fact that most of the Linux
   community are very helpful and responsive to e-mailed questions,
   you're asking for help from unpaid volunteers, so you have no right
   expect an answer.
   
   
   
   
13. Administrative information and acknowledgments.

   
13.1 Feedback is invited.

   Please send me your comments on this FAQ.
   
   I accept contributions to the FAQ in any format. All contributions,
   comments, and corrections are gratefully received. Please send e-ma
   to kiesling@terracom.net.
   
   If you wish to refer to a question in the FAQ, it's better for me i
   you do so by the question heading, rather than number. The question
   numbers are generated automatically, and I don't see them in the
   source file I edit.
   
   I prefer comments in English to patch files--context diff is not my
   first language.
   
   
13.2 Formats in which this FAQ is available.

   This document is available as an ASCII text file, an HTML World Wid
   Web page, Postscript, and as a USENET news posting.
   
   All of these formats are generated from SGML source using SGML Tool
   and the LinuxDoc DTD.
   
   The HTML version of this FAQ is available as
   http://sunsite.unc.edu/LDP/ at other sites.
   
   The Usenet version is posted regularly to news.answers, comp.answer
   comp.os.linux.misc, and comp.os.linux.announce. It is archived at
   ftp://rtfm.mit.edu/pub/usenet-by-hierarchy/comp/os/linux/misc/.
   
   The most recent text, HTML, SGML, and Postscript versions are
   available from the Linux archives at sunsite.unc.edu, and from
   http://www.terracom.net/~kiesling
   
   
13.3 Authorship and acknowledgments.

   This FAQ is compiled and maintained by Robert Kiesling
   kiesling@ix.netcom.com, with assistance and comments from Linux
   activists all over the world.
   
   Special thanks are due to Matt Welsh, who moderated
   comp.os.linux.announce and comp.os.linux.answers, coordinated the
   HOWTO's and wrote substantial portions of many of them, Greg Hankin
   and Timothy Bynum, the former and current Linux Documentation Proje
   HOWTO maintainers, Lars Wirzenius and Mikko Rauhala, the former and
   current moderators of comp.os.linux.announce, Marc-Michel Corsini, 
   wrote the original Linux FAQ, and Ian Jackson, the previous FAQ
   maintainer. Thanks also to Roman Maurer for his many updates and
   additions, especially with European Web sites, translations, and
   general miscellany.
   
   Last but not least, thanks to Linus Torvalds and the other
   contributors to Linux for giving us something to talk about!
   
   
13.4 Disclaimer and Copyright.

   Note that this document is provided `as is'. The information in it 
   not warranted to be correct. Use it at your own risk.
   
   Linux Frequently Asked Questions with Answers is Copyright (c) 1997
   1998 by Robert Kiesling kiesling@terracom.net, under the
   copyright of the Linux Documentation Project. The full text of the 
   copyright is available via anonymous FTP from sunsite.unc.edu, in t
   directory /pub/Linux/docs/LDP, and is included below.
   
   Portions are Copyright (c) 1994, 1995, 1996 by Ian Jackson, the
   previous Linux FAQ maintainer.
   
   Linux Frequently Asked Questions with Answers may be reproduced and
   distributed in its entirety (including this authorship, copyright, 
   permission notice), provided that no charge is made for the documen
   itself, without the author's consent. This includes "fair use"
   excerpts like reviews and advertising, and derivative works like
   translations.
   
   Note that this restriction is not intended to prohibit charging for
   the service of printing or copying the document.
   
   Exceptions to these rules may be granted. I would be happy to answe
   any questions regarding this copyright. E-mail me at
   kiesling@ix.netcom.com. As the license below says, these
   restrictions are here to protect the contributors, not to restrict 
   as educators and learners.
   
                  LINUX DOCUMENTATION PROJECT COPYING LICENSE

   Last modified 6 January 1997


   The following copyright license applies to all works by the Linux
   Documentation Project.

   Please read the license carefully---it is somewhat like the GNU
   General Public License, but there are several conditions in it that
   differ from what you may be used to. If you have any questions, ple
   email the LDP coordinator, mdw@sunsite.unc.edu.

   The Linux Documentation Project manuals may be reproduced and
   distributed in whole or in part, subject to the following condition

   All Linux Documentation Project manuals are copyrighted by their
   respective authors. THEY ARE NOT IN THE PUBLIC DOMAIN.
     * The copyright notice above and this permission notice must be
       preserved complete on all complete or partial copies.
     * Any translation or derivative work of Linux Installation and
       Getting Started must be approved by the author in writing befor
       distribution.
     * If you distribute Linux Installation and Getting Started in par
       instructions for obtaining the complete version of this manual
       must be included, and a means for obtaining a complete version
       provided.
     * Small portions may be reproduced as illustrations for reviews o
       quotes in other works without this permission notice if proper
       citation is given.
     * The GNU General Public License referenced below may be reproduc
       under the conditions given within it.

   Exceptions to these rules may be granted for academic purposes: Wri
   to the author and ask. These restrictions are here to protect us as
   authors, not to restrict you as educators and learners. All source
   code in Linux Installation and Getting Started is placed under the 
   General Public License, available via anonymous FTP from the GNU
   archive site.



                            PUBLISHING LDP MANUALS

    If you're a publishing company interested in distributing any of t
   LDP manuals, read on.

   By the license given in the previous section, anyone is allowed to
   publish and distribute verbatim copies of the Linux Documentation
   Project manuals. You don't need our explicit permission for this.
   However, if you would like to distribute a translation or derivativ
   work based on any of the LDP manuals, you must obtain permission fr
   the author, in writing, before doing so.

   All translations and derivative works of LDP manuals must be placed
   under the Linux Documentation License given in the previous section
   That is, if you plan to release a translation of one of the manuals
   it must be freely distributable by the above terms.

   You may, of course, sell the LDP manuals for profit. We encourage y
   to do so. Keep in mind, however, that because the LDP manuals are
   freely distributable, anyone may photocopy or distribute printed
   copies free of charge, if they wish to do so.

   We do not require to be paid royalties for any profit earned from
   selling LDP manuals. However, we would like to suggest that if you 
   sell LDP manuals for profit, that you either offer the author
   royalties, or donate a portion of your earnings to the author, the 
   as a whole, or to the Linux development community. You may also wis
   to send one or more free copies of the LDP manual that you are
   distributing to the author. Your show of support for the LDP and th
   Linux community will be very appreciated.

   We would like to be informed of any plans to publish or distribute 
   manuals, just so we know how they're becoming available. If you are
   publishing or planning to publish any LDP manuals, please send emai
   to Matt Welsh (email mdw@sunsite.unc.edu).

   We encourage Linux software distributors to distribute the LDP manu
   (such as the Installation and Getting Started Guide) with their
   software. The LDP manuals are intended to be used as the "official"
   Linux documentation, and we'd like to see mail-order distributors
   bundling the LDP manuals with the software. As the LDP manuals matu
   hopefully they will fulfill this goal more adequately.


    Matt Welsh, mdw@sunsite.unc.edu
   

