snowmizer
Enthusiast
Enthusiast

Using VCB on a SQL Server VM

I am using VCB to backup a VM that is running SQL Server 2000 on Windows 2003 Standard. When I look at the application log I see messages about the database being inaccessible and marked as "suspect". A couple of minutes later everything in the event log shows this database starts performing normally. I have isolated this incident down to the time VCB would be snapshoting the VM and starting the backup. I know that you can use pre-freeze and post-thaw scripts to quiese the system before running VCB. I have tested this with Exchange and it works fine.

Am I correct that I need to add commands to the pre-freeze and post-thaw scripts to shutdown the MS SQL Server services? I'm assuming that if I have to do this I just need the services shutdown long enough to create the snapshot.

Thanks.

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3 Replies
kjb007
Immortal
Immortal

That is correct. SQL does not always behave well when a snapshot is created, and may not like it when you delete the snapshot when done. Using the pre-freeeze post-thaw script would help that situation.

-KjB

vExpert/VCP/VCAP vmwise.com / @vmwise -KjB
RussH
Enthusiast
Enthusiast

Hello!

There used to be 2 undocumented transact sql commands within SQL server - DBCC FREEZE_IO and DBCC THAW_IO - They certainly existed on SQL 2000 which you appear to be using.

Rather than incurr a lengthy outage by actually stopping the SQL services (which would also work for sure) - you may want to try the above TSQL commands in your pre/post vcb scripts. You could use isql.exe or osql.exe to run these commands in from the script.

Never tested any of this, but worth a shot?

Cheers

Russ.

snowmizer
Enthusiast
Enthusiast

Thanks for the replies. I'll look into the DBCC_xxx commands to see if they work well.

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