We had noticed that Enterprise vault (9.0.3) in our environment had stopped journaling of messages from Journal mailbox & numbers had past 200,000 items.
On going thru logs we found the below warning:
A Journal mailbox has a backlog of messages held in its Inbox
This is because by default if somehow messages past the 150,000 limit mark than EV stops the journal of messages.
For fixing this you have to set the below registry key to a higher number , We had to set it to 300,000 which was above the number of messages pending for Journal.
1. Go to Start | Run on the EV server with the Journal ask, type regedit and click OK.
2. Expand HKEY_LOCAL_MACHINE\Software\KVS\Enterprise Vault\Agents.
3. Right-click the Agents key and choose New > DWORD Value.
4. Enter the name JournalWarningMsgCount (case sensitive).
5. Double-click JournalWarningMsgCount and enter a decimal value specifying the maximum number of messages allowed in the Journal Inbox before a warning message is logged.
For 64 but systems key will be under Wow6432Node