Link to home
Start Free TrialLog in
Avatar of kam_uk
kam_uk

asked on

Resetting Exchange Transaction Log Numbering sequence

Hi

We are running Exchange 2003 SP2.

I have heard that the transaction log numbering sequence is limited to 1million.

http://exchsrvr.org/E2K3/How%20to%20Reset%20the%20Transaction%20Log%20Numbering%20Sequence.htm

The solution to this is to move all log files and checkpoint to another location.

My question is - what act actually resets the log sequence? Is it effectively deleting the checkpoint file so that the logs start from #1 again? What in layman's terms does the chk file do?
Avatar of FearNoMore
FearNoMore
Flag of India image

What does the .chk file do?
The E##.chk file maintains the checkpoint for the Storage Group. The ## represents the Storage Group number with the First Storage Group file called E00.chk. This checkpoint file keeps track of the last committed transaction. If you are ever forced to perform a recovery, this file contains the point at which the replaying of transaction logs starts.
http://www.msexchange.org/articles/Understanding-Exchange-Information-Store.html
So ineffect the .chk file keeps track of the last transaction log that was committed to the database
What act actually resets the log sequence?
It is the combined process of moving both the log files as well as the .chk file that resets the log sequence
This MS article also talks about resetting the log sequence
http://support.microsoft.com/kb/830408
 
Avatar of kam_uk
kam_uk

ASKER

Hi

So - if I moved the log files but not the chk file - would this cause database corruption?
Not in all scenarios will it cause database corruption.....and one cannot be 100% sure.
The chk file keeps track of the last committed transaction log file and the point from where the log files should start the replay process.
The chk file is just like a pointer for transaction log replay.
 
Avatar of kam_uk

ASKER

Hi FearNoMore...

I was just thinking there would be database corruption because if the logs were moved manually but *not* the checkpoint file, then Exchange would be looking for logs that were no longer there? Whereas if the chk file was moved, then Exchange would essentially just start the log sequence from scratch?

ASKER CERTIFIED SOLUTION
Avatar of FearNoMore
FearNoMore
Flag of India image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial