Exchange 2003 Logs filling up

[stryker333]

We have an Microsoft Exchange Server 2003 running on Windows Server 2003.

I understand the Exchange Logs gets to build up and will only clear if there is a successful backup of the Information Store or some Exchange files.

Is there a place to "check mark" so that the Log files don't fill up or can replace itself so that it doesn't fill up my server and crash the Exchange Server?
(Cuz' our Backup doesn't work properly - a separate issue for now).

Any help is appreciated.

-Randy

 

[daviesda]

you need to enable circular logging on the information store

admin group> server object > first storage group >enable circular logging tick box

you will need to stop and start the exchange services for it to take effect.
also make sure you understand the implications of this as it can affect what you will be able to recover with a backup.

i personally would stop the exchange services and copy the .edb & .stm files to another location somewhere on your network a least once a day - sometime at the end of the day, until you can ix your backup

alternatively a create a batch file that will stop the services, copy the files and then start the services again.

 

[stryker333]

Thanks for the reply.

Keeping in mind your note on the "restore" process, is there a way to have the "ciruclar log" feature use a total of 10GB of space before the log files over-write itself?

We have 10GB to spare, and this way, if we need to do a restore, I'm sure we will find a couple of those 5MB files within the 10GB space.

-Randy

 

[daviesda]

Randy
Circular logging is either enabled or disabled. There isn’t an in between. They work like this.

When an event happens, rather than exchange having to find the correct place in the database file to update, it instead writes the event to the end of the transaction log. It does this because it’s much quicker to write an event to the end of a transaction log. When multiple events are happening each second they would soon start to back up if it was written to the correct place in the database file each time.

What then happens is that when there is a lull in the activity of the server, the system attendant will come along and will commit the events in the transaction logs to the correct place in the database files.

With circular logging disabled, the log files will continue to build up until something deletes\flushes them. Exchange aware backup programs (backup exec, arcserve, built in windows backup) will flush committed logs when they back the database files up. Alternatively you could delete them yourself as long as the exchange services are stopped.

The idea behind disabling the circular logging is that in the event of a database corruption, you would be able to restore the database from your last full backup, then when the exchange services start up they would replay the logs into the database – meaning you get to restore right up to the point of corruption, without even losing an email.

The idea behind enabling circular logging is for servers without too much disk space to play with or where backups are not being done\are not an issue. With cl enabled, exchange will work with only 5 log files. When they are full exchange will then go back to the first log file and overwrite it. When that is full it will overwrite number 2 and so on, always circulating the 5 files.

When exchange is shut down cleanly, any remaining transactions to be written to the database are committed. So when the services shutdown cleanly, all the events in transaction logs are in the database files.

My advice would be if you are short of disk space and have a problem with the backups

• Enable circular logging
• Stop the exchange services daily and copy the contents of <program files>exchsvr>MDBDATA to another machine on your network (another disk if part of a raid array would be ok. Ideally on a machine in a different building) – size will be an issue when copying. Remember you can schedule this overnight
• Fix your backup problems ASAP
• Disable circular logging
• Use an exchange aware backup program that will flush the logs


Hope this helps
David

 

[daviesda]

No problem! glad I could help.

 

[stryker333]

Thanks for everything. Things are looking brigher so far.

-Randy