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 Data Corruption Issues
 Recovering from a recovery from tape

Author  Topic 

amccrackin
Starting Member

3 Posts

Posted - 2012-12-05 : 09:48:02
I'm afraid I know the answer to this one but I want to ask anyway (I'm not a dba but I'm at the bottom of the hill so to speak)...

Our SAN lost several drives and our TFS 2008 SQL Server (SQL 2005) vm was restored from tape. Apparently the tape backup routine is SQL unaware because I have 0 allocation errors but I do have consistency errors in some db's. I found this out after the server was brought back up and was already being actively used again.

I do have SQL backups for before the failure.

Do I have any options besides either:
1) repairing as best as it can and keeping the backup as reference
2) reverting to pre-crash and having people re-apply their changes

Is there anyway to restore my backup as a different db & compare it to the active db to see what it has that's missing from the active db?

Thanks

Andrew McCrackin

nigelrivett
Master Smack Fu Yak Hacker

3385 Posts

Posted - 2012-12-05 : 10:34:40
You should be able to restore to another db and compare but I was at a company recently which said their 3rd party backup solution did not allow that (nor to another server). I told them to get rid of the backup solution if that was the case - they couldn't test it.

Do you know if the database had problems before the crash?
If your backup solution is not sql aware and just backing up files (and you are not taking sql backups) then you probably can't guarantee that any can be restored - basically you don't really have any backups.
Have you ever tested the backup solution?

==========================================
Cursors are useful if you don't know sql.
SSIS can be used in a similar way.
Beer is not cold and it isn't fizzy.
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amccrackin
Starting Member

3 Posts

Posted - 2012-12-05 : 10:50:25
I found the problem because of post-restore backup and index rebuild issues. We are going to do a DR review and discuss this issue. I am also thinking about proposing investing in a mirrored server for a on-line backup (log shipping maybe). I do have SQL full and txn backups running, but didn't get get to check the db before it went live this time.

I am currently prepping another server so that I can run the repair on a copy of the db to see what I get.

Thanks for the reply.

quote:
Originally posted by nigelrivett

You should be able to restore to another db and compare but I was at a company recently which said their 3rd party backup solution did not allow that (nor to another server). I told them to get rid of the backup solution if that was the case - they couldn't test it.

Do you know if the database had problems before the crash?
If your backup solution is not sql aware and just backing up files (and you are not taking sql backups) then you probably can't guarantee that any can be restored - basically you don't really have any backups.
Have you ever tested the backup solution?

==========================================
Cursors are useful if you don't know sql.
SSIS can be used in a similar way.
Beer is not cold and it isn't fizzy.



Andrew McCrackin
Go to Top of Page

nigelrivett
Master Smack Fu Yak Hacker

3385 Posts

Posted - 2012-12-05 : 11:35:58
Are the backup files also being copied to tape? You could restore those files then restore the database from them.

==========================================
Cursors are useful if you don't know sql.
SSIS can be used in a similar way.
Beer is not cold and it isn't fizzy.
Go to Top of Page

amccrackin
Starting Member

3 Posts

Posted - 2012-12-05 : 11:47:33
I have those available, but I want to try to preserve the changes made since the restore. If the repair goes badly, then I'll end up restoring from those and having to manually re-apply all changes since...

quote:
Originally posted by nigelrivett

Are the backup files also being copied to tape? You could restore those files then restore the database from them.

==========================================
Cursors are useful if you don't know sql.
SSIS can be used in a similar way.
Beer is not cold and it isn't fizzy.



Andrew McCrackin
Go to Top of Page
   

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