Migration from an older Archetypes Version to a newer one.

The following migrations are know to work:

 * From 1.2.x to the current release: full migration supported

 * Frem early versions of 1.3 (1.3alpha to beta2): full migration except of
   metadata on reference objects. This was a new, experimental and undocumented
   piece of code that has changed in 1.3-beta3 and you'll probably have never 
   touched it.

Steps:

 1 BACKUP your database

 2 Update your Archetypes and all depending products like validation, 
   MimetypesRegistry and PortalTransforms

 3 Restart your Zope

 4 Navigate in ZMI to archtypes_tool, click on 'Migration' Tab.

 5 'start migration' and be patient.

 6 Check if your sites works and report "bugs":http://sourceforge.net/tracker/?func=browse&group_id=75272&atid=543430

Remarks:

 * Missing feature: Coming from a 1.3.bx: metadata on references are gone

 * Migration takes a real long time, depending on the number of archetypes 
   based objects in your site. If your CPU is on 100% it runs.

 * Provide enough RAM and CPU power.

 * Depending on the number of objects needing migration you should provide 
   enough space in /tmp or whereever your zope saves subtransactions and provide 
   enough space on the disc the ZODB is stored.
   E.g for 10.000 old archetypes objects you 500-1000MB temp-space and the same 
   additional available for ZODB are a good starting point. 
   Packing ZODB isnt covered by migration.
  
--Jensens




