Posted by: Denny Cherry
LiteSpeed, Quest Software, SQL Server
So you use LiteSpeed and expect that at some point you will be using object level recovery. Without any changes you can do this no problem, LiteSpeed will simply need to create what is called the OLR Map first. This is simply a map of where OLR can find each object within the backup file. This is done by adding the @OLRMap=1 parameter to the backup job. Currently there’s no way in the backup wizard to do this (something which will hopefully be changed soon).
Now if your database is smaller, then creating this map is no problem. It just takes a few seconds, or a few minutes. However if your database is say 1 TB in size like mine is, then you’ll want to allow the SQL Server to create the map while the data is being backed up.
Now creating the OLR Map is a pretty quick operation when done as part of the database backup, somewhere about 10-20 seconds if you believe Quest (I didn’t really see any change in database backup time). When done after the fact this can take a very long time. In my case creating the map afterwords takes over 12 hours. Now the good news is that if you do it on object level restore you only need to do it the first time you restore an object from the file, as the object map is written to the backup. Now the downside to this is that you have to write to the backup file. In my case I found of this the hard way, I had the volume with the backup mounted in read only mode on the server that was running the OLR process. Because of this the OLR process had to be stopped and the volume remounted, then the OLR process restarted.
So in short.
- Add the @OLRMap=1 parameter to your backups.
If you can’t, or need to restore from an existing backup.
- Make sure the volumes are read/write
Or do a full restore, then use SSIS to move the data to the production server.