Tales of when a Log Fails to Shrink in an Availability Group

I received a report that one of my servers had 7% free space on its log drive. Sounded like something fun to resolve. I checked on what was going on and found a log file that was 99% free and a hundred gb in size. While shrinking a log file is not a good practice and I’m not advocating it by any means because it’s just going to grow again and your storage is there specifically to hold logs, this situation was a out of the ordinary and we needed space.

The problem was, this log would not shrink. It was being extremely uncooperative. I took a backup, log backups, multiple shrink attempts, but it wouldn’t budge. The message returned was a big clue though.

<code>The log for database ‘dbname’ cannot be shrunk until all secondaries have moved past the point where the log was added.</code>

As you might have guessed, this server was a SQL Server 2012 instance and in an Always On Availability Group. The database in question could not shrink because it was participating in the AG.

It wasn’t an ideal fix, but by removing the database from the Availability Group, I was able to perform a log shrink to get the size to a more manageable amount. No, I did not truncate it to minimum size, I adjusted it to a reasonable amount based on its normal work. I didn’t want the log to just have to grow again. The shrink worked flawlessly, and with adequate drive space, I attempted to add the database back to the AG via the wizard.

The AG wizard refused to help. The database was encrypted and the AG wizard will not let you add a database if it is encrypted. No explanation why, it just doesn’t like that. You can add an encrypted database to an AG via script though. You can even script the change from the wizard by using a non-encrypted database then changing the database name in the scripted result. The resulting script is exactly what the AG wizard would do, it just cannot execute it automatically.


ALTER AVAILABILITY GROUP AgName
ADD DATABASE DbName;
GO

With free space and an encrypted database safely back in my AG, I was off to new adventures!

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