I am in the process of planning to upgrade from 5.0.16 to 6.0.4.

Current version:
Release 5.0.16_GA_2921.SLES10_64_20090429024033 SLES10_64 NETWORK edition

My setup is made up of a Master LDAP, one replica LDAP, two MTAs and four mailbox servers. I have about 40,000 accounts. Besides the LDAP upgrade issue, which I believe is fixed. Is there anything else I should be looking out for?

In the pass I've noticed that the upgrade does a permission check on the files. Can I run this prior to upgrading and then have the upgrade skip this process?

Also to save time, I was thinking about umounting the HSM and my backup directories. Does anybody see any problems with this?