Using more than one program to backup SQL data


What woudl happen if you had more than one backup software doing differential backups of a SQL server? Are both sets of backups going to be fully functional or would they need to be combined to fully restore the data?

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Differential backups should be OK, as a differential backup backs up everything since the last full backup.  To restore from a differential backup you need just the differential backup and the last full backup.

Incremental backups are different, as they backup only what has changed since the last full OR incremental backup.  To restore from incremental backups you need the latest full backup and every subsequent incremental backup.

I would still recommend against running differential backups with two different backup products, though.  In theory you should be able to get away with it, but I suspect in practice you may have problems crop up.
yo_beeDirector of Information TechnologyCommented:
To add some comments to what Joelgaskell I would use only one product.
I ran into a situation where the last full was on tape and I was u able to restore a database successfully.
What I ended up changing was using SQL internal backup and then backed up the baks and trns files to tape using symantec. So if I need to restore I need to restore the files first then run a restore sequence using SQL.
BobBrinkAuthor Commented:

thank you for the comments. -So to be perfectly clear, my original assumption was that the SQL database keeps track of what was backed up via a flag put into the data and this is not the job of the backup software. Example:

Do full backup with software product A.
6 hours later do differential with software product B, product B finds te difference by looking into the SQL datat to determine when the last FULL backup was done.

Is this example correct?

Thanks again,

yo_beeDirector of Information TechnologyCommented:
That is correct. It is fine is you do not need the full, but from my experience it Would be best to use one or the other.

IMO I found that the way I am doing it currently works quite well.

To add to my procedure. I keep the Bak files for 7 days until I have another set.  

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Microsoft SQL Server 2008

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