MSL 4048

[MARK GRIZENKO]

We have a MSL4048 with 2 LTO-3 drives. Is it possible to connect the drives to separate SCSI controllers on the server? Also, how would this present to the server, one single drive library and a stand alone drive? Any input would be appreciated.

[Curtis Ballard]

Yes it is possible to connect each drive to a separate SCSI controller on the server and that is actually the recommended connection method. If you use a dual port SCSI card you still only have to use one slot.

As long as both HBA's are on the same server that server would still see one library controller and two tape drives. An application could associate the drives with the library with the normal matching techniques applications use.

If you want to connect the two drives to two different servers you should partition the library then each server can see one controller with access to 1/2 of the library and one tape drive.

Note partitioning a 4048 has a funny behavior if you have 2 half height drives. You have to have one drive in the top 1/2 of the 4048 to partition the library so the option isn't even shown if you have two HH drives both in the bottom half of the library. Move one drive up and the blanking plate down and partitioning becomes an option.

[thomasr]

As Curtis says, it's possible to partition the MSL4048 library -- and that's true even if it's connected to a single server. The partitioning is done in the MSL GUI, and with two drives you'd see what looked to your backup application like two separate 1-drive, 24-slot tape libraries.

Why would you want to do this? Suppose you upgraded your library by adding an LTO-4 tape drive -- then you could keep the LTO-4 tapes separate from the LTO-3 tapes. You might even want to use the MSL Encryption Kit to make sure that every backup sent to one of the LTO-4 drives was encrypted. Partitioning lets this happen easily.

With both drives connected to one server and without partitioning, you'll see both drives as part of the same library, which is usually what you want for identical drives.