Today I have seen the mailbox service restart itself numerous times today. Example form /var/log/zimbra.log:
Sep 21 09:09:39 serenity zmmailboxdmgr[16975]: manager woke up from wait on mailboxd/JVM with pid 9391
Sep 21 09:09:39 serenity zmmailboxdmgr[11904]: wrote java pid 11904 to /opt/zimbra/log/
Sep 21 09:09:39 serenity zmmailboxdmgr[16975]: manager started mailboxd/JVM with pid 11904
/opt/zimbra/log/mailbox.log shows the following:
2009-09-21 09:09:38,757 FATAL [btpool0-81] [] system - Unable to commit database transaction.  Forcing server to abort
I have been able to cause this behavior directly by attempting to view the free/busy info for one particular user. Here's the steps:
1) create a new mtg in Outlook (ZCO
2) add some other user (verify that we view another users' free/busy)
3) try to add the problem user
result: mailboxd immediately fails and I am unable to view the problem users' calendar info

The problem isn't limited to Outlook, however. If I login to the user's account via the Zimbra web client, as soon as I click on the Calendar tab, the mailbox service fails.

Any advice on what to do to resolve this problem?