DB Upgrade Lessons Learned [SPS 2003 to MOSS 2007 Migration]

• To start with migration, first build SPS Dev Env and Match the source SPS2003 Service pack/Hot Fix
  
• To perform PreScan for migration, SPS 2003 SP2 is must.
  
• On SPS2003, you cannot restore more than one copy of the same portal. Each portal has an unique ID that is stored in the Config_DB.
  
• When restoring portal, if restore fails, look at the end of the log for most recent restore error. Restore process maintains single log file for successive restores.
  
• After STSADM databaserepair you need to remove and re-attach the content database so that the Config DB sheds off the deleted sites. More than one person has experienced the Remove content DB action from the central admin interface doesn't really remove the content db. May be since the databases are huge. In this case simply perform the Delete portal with retain databases and add/restore clean new portal.