Question : Exchange log files deleted

We had a problem last week where the Exchange 2000 log files filed the drive, and the service quit.  Not knowing any better, I deleted some of the older log files so I could get the server running again.  Exchange seems to be working just fine, but after reading a few articles online I realized I should not have deleted the files.

I have three questions regarding the log files.

1. I believe the log files were generated during the Exchange backup cycle.  Why does it generate so many messages?  Is this an indication of a problem with the store?  How do I fix this.

2. Since Exchange seems to be running okay, do I need to try and recover the log files, or with time, will I eventually get to the point where the deleted log files will no longer be needed?

3. I'm using Veritas Backup Exec to back up exchange.  Should I backup the individual mailboxes as a safeguard?

Thanks for your help

Answer : Exchange log files deleted

First, let me explain what the transaction logs are: Exchange writes information to transaction logs before it is commited to the database. This ensures that data is protected. When a transaction occurs, it is recorded to a log file and the modified database pages are writted to a memory cache. When system load permits, the pages are then commited to the database. Each transaction log is exactly 5MB. Transaction logs also serve an important purpose in recovering a failed database. If you need to restore a database from tape, it can be restored up to the second of failure because the transaction logs from the time the database was backed up until the failure occured are replayed.

Transaction logs will continute to accumulate until they are purged. They are only purged by one of three ways - manual deletion, circular logging or by performing a full backup of the storage group. Manual deletion should never be performed unless there is no other choice. Before logs files can be manually deleted it must be confirmed that they have been commited to the database (this is done by running eseutil). In your case, you were just lucky that the log files you deleted happed to have already been commited. Circular logging overwrites log files as necessary but this is not generally recommended because it prevents an up to the second restore. The best way to purge log files is with a full backup of the storage group. An Exchange aware backup program will automatically cause the purging of the log files. You should verify that full backups are successfully running on a regular basis.

You can move the transaction file to a bigger disk from the Properties page of the Storage Group in ESM and yes, they can be on a differend drive than the database and in fact that is the recommended configuration.

The option you changed on the General tab of the Properties page for the server does not relate to transaction logs but to message tracking logs. These are two different things.