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Exchange 2007 on Windows 2008 Server Circular logging enabled

Exchange aware Backup Application (Symantec BESR 2010), on test restores, when I do eseutil /mh on the mailbox database, its in a dirty shutdown state.

I am thinking that it is because of circular logging, as I did a test backup on another exchange box which has no circular logging enabled and the logs were truncated by the backup app, on a test restore the db was in a clean shutdown state.

am i right in thinking that I should disable "circular logging" (logs will be truncated by BESR 2010 -it has the option) ?

Now, can I disable this in production hours ? is it just a matter of unchecking the box and the change effects straightaway ?

Thanks & Regards

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up vote 1 down vote accepted

Yes - the normal state, if you want your backups to work, is to have circular logging disabled. It has its uses - in lab environments, when you are doing large migrations, when you are using something other than VSS aware backups like Backup Exec (ie Exchange Native Data Protection mechanisms) or when backups of particular mailstores are not so important but the normal state is to have it disabled.

The Exchange Team Blog has a nice write up on it here.

The idea here we want to reinforce is that when you are performing VSS backups that rely on the transaction logs, make sure that your normal run state is with circular logging turned off. If you have a reason to turn circular logging on when utilizing VSS incremental backups that rely on the transaction log files, remember to turn it back off as soon as reasonable, and understand that while circular logging is on that your incremental backups will fail to complete as expected

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On the link you have provided, it says the following in one of the comments : ""Each time circular logging is enabled or disabled, the database has to be dismounted and mounted back for the changes to take effect. See…; So, I think I will disable circular logging on the day off a scheduled restart - so won't just have to dismount dbs. Restart will take care of that - I hope I am thinking right with this one :-) – rihatum Sep 17 '10 at 11:57
Yep - a restart will do it for you if you don't want to incur any unplanned downtime. – Helvick Sep 17 '10 at 12:07

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