Use Windows Backup to Truncate Logs in Exchange 2010 with DAG Configuration

I ran into a few minor glitches that weren’t mentioned in other posts when using this method in my own environment.  So first I will mention what was different for me, then I will be going over the full set of instructions to use this method.  My goal for this post is to be as thorough and unambiguous as possible so there are no questions after reading these instructions.

First, it wasn’t readily apparent what specifically needed to be backed up in the pieces I read.  Though, it is quite possible I managed to misread the sections that described them.  After some experimentation in our test network I learned that all volumes containing databases and log files need to be backed up.  This means that if you have separate drives for logs and databases, both of them need to get backed up, I would have saved a lot of time had I known this beforehand.  And, as far as I can tell, both the mailbxes and logs have to be backed up for this method to work, not just one or the other.  So just to reiterate this with an example, you have to back both the (L:) and (M:) volumes up.

The other thing that was mentioned in other posts but wasn’t clear cut was the need to change the registry key to disable VSS trasnport replication.  It is necessary for Exchange environments using a DAG configuration with both active and passive databases, if this change isn’t the case the backup may work but your logs won’t get truncated.  Finally, ensure that you have the Microsof Exchange Server Extension for Windows Backup service started.

  • Log on to the server by using an account that has local administrator access, and open regedit
  • Navigate to HKEY_LOCAL_MACHINE\Software\Microsoft\ExchangeServer\v14\Replay\Parameters.
  • Add a new DWORD value named EnableVSSWriter, and set its value to 0.
  • Exit Registry Editor and then restart the Microsoft Exchange Replication service.

Okay, now we need to enable the Windows Backup feature (I will leave that to the reader), just make sure not to enable the backup command line tools (they are outdated).

So now you just create your backup job and after everything is all said and done your logs should get truncated, it seems like a lot more work than should be necessary but if your logs don’t get truncated then really bad things happen, so it is a small price to pay I guess to make sure things are working the right way.

That’s pretty much it.  Once the backup has completed your log volume should have more room.  There are other ways to clear the transaction logs, maybe I will go over them in another post but this method is (for the most part once you figure out what you’re doing) easy and built into Windows.  Just make sure you have enough free space somewhere on your network to house the backups, especially if there there is a lot to move.

About the Author: Josh Reichardt

Josh is the creator of this blog, a system administrator and a contributor to other technology communities such as /r/sysadmin and Ops School. You can also find him on Twitter and Facebook.