Exchange Logs Issue

billybob01 · February 2009

I am moving mailboxes between servers and i have the database and logs on seperate drives on the new server, but i have noticed that the logs are filling up the drive, why is this? and can these be deleted, or will a backup clear the logs?

HeroPsycho · February 2009

Since moving mailboxes are transactions against the database, they go to the logs first, just as all transactions do.

Yes, a backup should delete the logs that have been committed so long as the backup software used is Exchange aware, such as NTbackup, BackupExec, NetBackup, etc. Do NOT delete tlogs unless you know what you're doing with eseutil to confirm which logs have been committed, and you understand the risks of deleting the logs without backing up the DB.

Claymoore · February 2009

A backup will clear the logs as HP said.

To prevent the logs from filling up during later migrations, you can enable circular logging on the storage group. This will delete the transaction log as soon as it is commited to the database. However - this is very important - turn off circular logging when the migration is complete. IMHO, circular logging should only be used during large mailbox moves or migrations. You will need to stop and restart the information store service when you toggle circular logging off and on resulting in brief loss of connectivity to the mail store.

HeroPsycho · February 2009

Claymoore wrote: »

A backup will clear the logs as HP said.

To prevent the logs from filling up during later migrations, you can enable circular logging on the storage group. This will delete the transaction log as soon as it is commited to the database. However - this is very important - turn off circular logging when the migration is complete. IMHO, circular logging should only be used during large mailbox moves or migrations. You will need to stop and restart the information store service when you toggle circular logging off and on resulting in brief loss of connectivity to the mail store.

I use circular logging on E2K3 dedicated mail gateway servers, too.

billybob01 · February 2009

Thanks guys, the problem i have is although a full backup has been made using either NTBackup or BackupExec 11d there are still loads of logs that all have the same date and time? I have changed the location to another drive and continued with the migration, but it does not resolve the issue with the logs not committing. I am using Backup Exec 11d, and have noticed that after the backup, all the archives have dissapeared but is still leaving loads of log files. Help please!

rjbarlow · February 2009

If You enable circular logging then the problem should be fixed. Try dismounting the Information Stores, that replays all the pending transactions into the databases. At this time enable circular logging and try mounting again the Stores.

HeroPsycho · February 2009

Are you actually selecting backups of the Information Store nodes in your backup software? If you're just selecting the file locations, then it's likely not communicating with Exchange to purge the logs.

Also, run Exchange Best Practices Analyzer (ExBPA) on your Exchange server. It will let you know if you're getting proper backups, or if for some reason Exchange isn't purging logs properly.

http://www.microsoft.com/downloads/details.aspx?FamilyID=DBAB201F-4BEE-4943-AC22-E2DDBD258DF3&displaylang=en

billybob01 · March 2009

All the mailboxes have been moved and so i have gone into Backup Exec and changed the name of any exchange backups to point to the new exchange server, and also backup the relevant folders, i have manually run one of the backups and have found that the logs still have the A next to them, which is telling me that the logs have not backed up even though they are selected within Backup Exec.

HeroPsycho · March 2009

billybob01 wrote: »

All the mailboxes have been moved and so i have gone into Backup Exec and changed the name of any exchange backups to point to the new exchange server, and also backup the relevant folders, i have manually run one of the backups and have found that the logs still have the A next to them, which is telling me that the logs have not backed up even though they are selected within Backup Exec.

Reread my previous posts. You can't just backup the relevant folders that the Exchange db's and logs are in. You MUST select to backup the Information Store node in your backup software. Otherwise, it's just doing file level backups of the directories, NOT talking to the Exchange program to tell it to purge the logs, not to mention that you're not getting a consistent backup of your Exchange server. Your backups are likely invalid.

If you don't know how to do this, I highly recommend you hire someone to validate your backup settings and infrastructure. I highly suspect your backups are invalid right now.

Once again, take the guess work out of if you're backing up properly. Run ExBPA. It will throw a warning if there are too many log files not purged or if you haven't had a valid backup of your stores.

billybob01 · March 2009

I hear what you are saying but when i check the backup jobs, the information store node is checked! I have also tried unchecking and reselecting the Information Store node but still no joy. My only option is to turn on Circular logging or using NTBackup to see if the logs disapear. Also some people are able to create new appointments in their calendar when using OWA, and others cannot!!

billybob01 · March 2009

Got it working at last!! Did`nt change anything regarding the backups but they just started to commit all of a sudden.

Exchange Logs Issue

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