Exchange Backups, why they’re important
I seem to run into this issue more often than I feel like I should. I show up at a client site and they have some complaint about Exchange. Usually, the issue is that email isn’t flowing anymore. When email stops flowing the first thing I look at it is to see if a disk is full. Frequently this is the culprit. When I look further to find out what is causing the disk to be full I find that the Exchange logs haven’t been removed because a full backup hasn’t taken place in quite a while.
Now this is where it gets fun. Ideally, we want a full back-up to run so it will flush the logs for us but until that happens we can’t get email to flow. The option I usually take is to dismount the databases and run a “eseutil /mh” against them to verify that they were dismounted cleanly. As long as they are dismounted cleanly, I can simply delete all of the log files and then re-mount the database. Problem one solved. At this point I can simply re-start the Transport Service and then focus on why backups haven’t been running.
I have had instances where the client went in and found the logs were filling up the system and just simply deleted or moved the older log files thinking they weren’t necessary. Let me say, this will cause issues at some point. I recently had a case where the client had been moving log files off regularly and not doing an Exchange backup. They had an issue where the storage holding their mailbox databases lost connectivity and the database dismounted in a dirty state. Because they had been moving log files off without a backup and without dismounting the store cleanly, the database would not remount. We tried using “eseutil /r /a” to do a soft-recovery but that wouldn’t fix things. In the end we had to run “eseutil /p” against the database to fix the issue. This was very painful as the database was 300+GB in size and so it took over 12 hours to fix.
Moral of the story, don’t overlook Exchange backups. They are highly critical. Whether it is for restoring an email or keeping the logs from filling up the drive, Exchange backups are vital to the health of your Exchange environment.
-Adam Ball, PEI