Scenario: Large NT WAN with 6 Exchange 5.5 servers. 5 servers in site container called HOME. 1 server in site container called REMOTE. Attempted to utilize Exmerge BackOffice utility to move mailboxes from server in REMOTE to a server in HOME. Processed failed, but all Exchange servers seemed unaffected.
Nightly backup of servers stops Exchange services, then restarts at conclusion of backup. Next morning we discovered that Information Stores on 3 servers in the HOME site would not start. 2 servers unaffected. Server in REMOTE site unaffected.
Received the exact errors as shown in MSKB Q185573. However, we were not doing an upgrade, and have no Exchange 5.0 servers.
Attempted to repair databases with ISINTEG and ESEUTIL utilities,but was unsuccessful. Did not yet want to restore from backup, as this would mean a days worth of email for 1000 users would be lost.
Eventually, we realized that it was not our Information Stores that were corrupted, but the Directory Services. Resolved the problem by completely uninstalling and then reinstalling Exchange, restored priv.edb, pub.edb, and dir.edb files from backup, then ran ISINTEG -PATCH. Everything was then back to normal.
We believe, but are unsure, that something became corrupted when we attempted to move mailboxes, and then the corruption somehow replicated. What is strange is that only 3 of the 6 mail servers were affected. What is also strange is that we found a MSKB article describing exactly the error messages, but the listed cause has nothing to do with our situation.
Although we have resolved the issue, if anyone can point me to possible causes or alternative solutions, I would appreciate it.