Exchange backups - understanding the log files
Posted on 2006-07-14
I have a single Exchange 2003 server, running on Windows Server 2003. For that past year, we have been using Veritas Backup Exec along with a DLT tape drive for our daily backups. We have also been using a product from Symantec called Live State Recovery as an additional method to backup our Exchange Server (and Domain controller server). The Live State Recovery product does server imaging...where it takes a snapshop of the entire server hard drives and creates a big image file that we copy over to an external USB hard drive. We want to get rid of the tape backups and move exclusively to server images stored on external hard drive. Hard drives are cheap, and restoring a single file or an entire server from these images are VERY easy. Tape restores have always been an ugly thing to do...especially when you are trying to recover the entire server from a disater.
My understanding of Exchange backups and transaction logs is that you need to do a full backup often, so that Exchange will clear it's transaction logs. Otherwise, the transaction logs will build up. With the Veritas Backup Exec product, the Exchange Agent somehow alerted the Exchange server that a full backup was performed and the transaction logs were then purged. However, I am not sure the our imaging backup does this. I am in the process of purchasing a support contract from Symantec to ask them if their software is capable of the same thing, but I was hoping someone could clarify the whole transaction log files and the relationship to the daily backups. For example if someone had an exchange server that they NEVER backed up, would their log files grow and grow until they filled up the hard disk? Is there a manual way of clearing the log files? If I understand it correctly, the transaction logs contain all the changes to the server since the last time they were "committed" to the database...is this correct? Other than using Veritas, how would someone "commit" the changes in the transaction logs to the database manually?
Thanks for the help!