There is indeed a restriction.

But it covers ALL drives in first AND second jukebox!

There has to be some restriction on the drives selection. Try a backup by removing all the device restriction from the media pool.

Have a look at the DB2 configuration file for any such specifications. As you have mentioned that the backup is not taking the tape from another jukebox, though volumes are available, are the volumes labelled in the required media pool. If not enable "auto media management", "recycle to other pool" and "recycle from other pools" attributes in jukebox and media pool properties respectively and try the backup.

The other way around is to check if the file system backup works. This will help you to isolate the problem.

Backup will readily take volumes from the SAME jukebox-spanning pool from either jukebox.

It just wont jump to use devices/volumes in another jukebox, once it starts ..

DB2 configuration defines only the pool, not the devices.

Are these two jukeboxes connected to the same storage node?  NetWorker will use the Storage Node affinity as defined in the client resource to decide which storage node to send the data to.

-Bobby

Same storage node. Same physical VTL. Same type of media (LTO3).

I'm not sure what's going on here Zlatko.  I agree with Mrdiul, you should experiment with different parameters of the situation to try to isolate what could be causing this, starting with seeing if it behaves the same way for a filesystem backup.

-Bobby

I agree that the first step should be to determine whether this is limited to DB2 backup or is it valid for all (filesystem) backups. However I do not have means to play with it at the moment.

Do you see this pattern only with DB2?  Can you dump here configuration for pool, jukebox and client affected?