2007 to 2008 Upgrade Advice

We are preparing to do our first upgrade and are looking forany tips, tricks, gotchas, best practices, advice, etc. Ourobjective is to ensure that the upgrade is successful whileminimizing the downtime (isn't it always?).

We currently have 4 replicated archive servers and our home basearchive server. SQL Server 2005 vault database resides on a clusterserver with a separate box running only the database serverapplication (We'd like to move this application to the home basearchive server, but not sure if we'll do it as part of thisupgrade).

We plan to do this over a weekend in order to lessen the impact onour users. Other than having complete, current backups before webegin, what else should we do? If a catastrophe should occur, howdifficult is it to rollback? As this is our first upgrade, shouldwe call in our VAR?

Thanks,
MikeSolidworksSolidworks Pdm enterprise Pdm