Exchange Server Transaction Logs

would I be correct in saying that ShadowProtect Server Edition does NOT roll up the transaction logs on Exchange Server 2003 ?

 And that to stop the log files filling up the disk I need to run something like NTBackup periodically to roll up the log files ?

 

TIA

Comments

bsdice

Re: Exchange Server Transaction Logs

Why would ShadowProtect mess with the inner workings of a database on the system? All that is happening is that a volume shadow copy is created to back up the database which is later removed. I am no Exchange guru but if your DB transaction logs are growing without bounds then SP is not part of the problem and neither of a solution. I wouldn't use ntbackup either, better find a scriptable way trim the logs once a day or something.

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TimJ808

Re: Exchange Server Transaction Logs

I believe he is referring to the transaction logs that Exchange creates, and does not delete until a full information store backup is performed.  These log files will grow and grow 5MB at a time.  Anyone who is a convert from Backup Exec (like me) knows that this needs to be addressed.

If you are solely relying on ShadowProtect now for your backups, you can use Exchange System Manager to enable circular logging.  ESM>Servers>ServerName>First Storage Group> right-click and choose Properties, and ensure a checkbox is in “Enable circular logging”.  If changed… a restart of the information store (or reboot) is required.  Circular logging will commit and delete log files, with a maximum of 5 logs files on the disk at any given time.

OR, you can still periodically perform a full information store backup using another backup program.

On another note, I’m still not sure the best way to get ‘brick-level’ restores of Exchange messages.

 

STC-Nate

Re: Exchange Server Transaction Logs

I second that recommendation to use circular logs.

I also recommend that you do not use ntbackup.exe as it very often leaves VSS writers in bad states. 

bmessenger

Re: Exchange Server Transaction Logs

Thanks for the replies

I'll opt to perform a backup of the information store as my understanding is that the problem with circular logging is it restricts disaster recovery. If you allow Circular Logging to over-write the transaction logs then Exchange 2003 can only restore as far as the last backup. When all the logs are available, Exchange 2003 automatically rolls forward the logs and replays the transactions up until the Exchange Store stopped working.

 

In fact, circular logging prevents Exchange 2003 making differential or incremental backups. So with circular logging in place, you are restricted to normal (full) backup.

akus1234

Re: Exchange Server Transaction Logs

Nate - Do you still not recommend NOT using ntbackup.exe? As a backup backup I have an ntbackup of the Exchange stores running once per week far away from the ShadowProtect bu times. 

 Thanks,

 Ray

STC-Nate

Re: Exchange Server Transaction Logs

If it works for you, great.  We've just experienced many cases where NTBackup will leave your VSS writers in bad states.  If this doesn't happen to you then you can ignore that advice.  Also, incidentally, ShadowProtect will still backups your machine even if some of your writers are in bad states.  This is usually not an issue, however, if your Exchange or SQL writers are in a bad state, that's when you *really* need to take notice and get things back into a good state (and also that would probably be a good time to stop using NTBackup).

bsdice

Re: Exchange Server Transaction Logs

Talk about sane defaults that simply work...

Brick level backups for Exchange: Do you have a NetApp filer? I know some of our customers run NetApp's SnapManager for MS Exchange with SnapMirror in a metro cluster configuration. The price might be prohibitive though...

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Raenar

Re: Exchange Server Transaction Logs

Hi,

When SP runs and does a VSS snap it should be classed as a "Full Backup" to exchange. To confirm this check the Mailbox Store properties under "Database" and it will tell you when the last one was. If your ShadowProtect backups aren't classed as Full Backups then something is wrong or VSS is not being used. Exchange should be purging your transaction logs if everything is working OK.

 

As for circular logging, the old recovery scenarios kind of go out the window using ShadowProtect. If you are snapping regularly there is no need for extended transaction logs. But at the same time, if you are snapping regularly your logs won't ever build up to cause a problem even if you aren't using circular logging.

 

The logging option is purely what you feel comfortable with, I don't think there is a benefit either way.
 

bmessenger

Re: Exchange Server Transaction Logs

Many thanks for the very informative replies

I think I will monitor this. On my own server wher I have been running SP for several weeks there is no build up of log files, but the Database properties don't show a full backup in that time, I can't see any VSS errors in the error log. I will do some test restores and see what happens

Many thanks again for the replies, it has answered all my questions 

 

 

TimJ808

Re: Exchange Server Transaction Logs

I agree with the old scenarios of backups going away.  Once you're on ShadowProtect... and using hourly incrementals, there is really no reason to bother with full Exchange information store backups and commiting transaction logs.  If you have to restore, you restore to the last ShadowProtect backup.

 

STC-Nate

Re: Exchange Server Transaction Logs

Please remember that for Windows SBS 2003 you must turn on the Exchange writer, as on SBS it is not enabled by default.  This is not an issue on other versions of Server 2003.  For more info, see:

 

http://support.microsoft.com/default.aspx?scid=kb;EN-US;Q838183 

Jack.Alsop

Re: Exchange Server Transaction Logs

Please note  - this post assume that the data and log files reside on the same disk partition.

Therefore if you chose to back up this partition (as an incremental backup) every hour say, the application call VSS which calls the VSS writer for Exchange and starts the freeze process to create the backup. Once the the snapshot has been taken and the backup completes the VSS Exchange Writer then deletes (truncates) the log files.  

Finally i would always recommend circular logging as we are backingup exchange every hour and the unnecessary log files are consuming disk space on our image repository.

With regard to the brick level backup secenario why not search the KB articles and look for one that talks about restores. You can take a backup from six months age and restore emails to a users mailbox using Microsoft's prefered method and StorageCraft image files. 

bmessenger

Re: Exchange Server Transaction Logs

Thanks Jack

this was spot on. After turning on the Exchange Writer for VSS The logs now show the transaction logs being rolled up and. And the Last Full Backup field on the Information Store Database shows the correct time of backup.

Thanks to everyone for their input, and patience, no doubt had I RTM I would have found this earlier. I am impressed with the product and the support from this group. Cheers 

 

atss

You folks are missing a very important issue here.

You folks are missing a very important issue here: With Exchange recovery using ShadowProtect, you WILL LOSE DATA. Even with hourly snapshots, you will lost an hour's worth of data. Exchange uses transaction logs to decrease the number of times a day it writes to the database, AND to rebuild data from the last backup. With NTBackup/WindowsBackup/BackupExec, a database restore triggers the log playback function, which ensures all data written to the transaction logs that had not been committed to the recovered database are written, resulting in a "lossless" recovery. This is why Microsoft always recommends a recovery instead of a database repair--because the recovery results in ZERO data loss. The issue is exacerbated if the database crashes overnight, as Exchange will continue to receive emails for delivery and hold them in the logs and/or queues got several hours before a tech recovers the database. Without a recovery that works with the playback function, all those messages will be lost permanently, without a trace or error. How is StorageCraft addressing this major issue?

ATSS

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STC-JaimH

There is no issue

There is no issue; ShadowProtect backs up the transaction logs too.

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Jaim Huntzinger | Technical Support Manager - Headquarters, SCME | StorageCraft Technology Corporation

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