I need to move my transaction logs to another drive because they keep filling up the partition they're on now. What's the best way to do this?

A. You've hit on the only real drawback of Exchange Server's transaction-oriented architecture. Because each change to the Information Store (IS) databases generates a transaction in the transaction log files, anything that makes lots of changes to your IS (such as a mail loop or moving lots of mailboxes) makes your log files balloon in size. If you don't have enough space on the drive where the log files are stored, the IS shuts down, logging a message in the event log at the same time. When this happens, you have a problem: You shouldn't delete the log files manually, but if you don't do something to make more space available, you won't be able to restart the IS.

How can you prevent this problem? If you do regular online backups, you should find that the backup process automatically removes the log files for you. If you’re backing up but the log files aren't disappearing, you aren’t getting good backups. Check your event logs for errors.

You can take one of three actions to fix a space squeeze once it starts happening: 1) Delete unnecessary files on the log drive. Be very careful if you choose this route. Don't delete any of the log files themselves! If you’ve followed the recommendation to put your log files on their own physical disk, this approach won’t help you because you don’t have any unnecessary files. 2) If you need to move the log files to another drive, use the Performance Optimizer to move them. This is the only safe way to move log files. Don't move log files yourself, and don't edit the registry subkey that shows where the files are. The IS databases contain references to the log file paths, so if you move things manually, you're heading for trouble. 3) Create a volume set to temporarily extend the log drive's partition. This is a neat trick that I first learned from Andy Webb.

To create a volume set, you first need to install an extra physical disk in your server (your IS is stopped anyway, so that shouldn't be a problem). Add the disk, then use Windows NT's Disk Administrator: