Fellow Tech-folk,
You may remember that I posted earlier (since deleted) that I was unable to get Backup Exec to see more than one drive and my library when using a fiber channel connection to a Compaq FCTC-II bridge.
The problem has been corrected. It was, in retrospect, pretty simple, but it required some insight into how Backup Exec looks for library devices and their associated drives. I'm providing this information in case others run into similar problems.
Just to put this in perspective -- The setup in question is a Proliant DL380 G2 server, running Windows 2000 Advanced Server with SP4 and the final rollup pack. It communicates with an ADIC Scalar 100 tape library with three DLT8000 drives. Said library and drives are linked up via an Emulex LP8000 FC board in the server, and a Compaq Fiber Channel Tape Controller II at the library end. The FCTC is a dual port, with the robotic handler on Port 0 and set to SCSI ID 3. All three drives are on Port 1, and are set to ID's 1, 2, and 3 from bottom to top.
I can just hear the eyebrows raising. SCSI ID's lower on the drives than the robot?
Keep in mind that those are physical ID's. The trick here is knowing that these ID's are NOT always transparently translated through the Compaq FCTC. Instead, the box maps physical ID's to SCSI LUNs in a most bizarre way.
In this case, the robot's ID of 3 is translated directly as LUN 3. No problem. HOWEVER -- If I had set the tape drives to ID's 4, 5, and 6, as one would need to do when connecting directly to a standard SCSI adapter in the server, the LUNs appearing to Backup Exec would have been all over the map.
With the drives set for 1-3, the FCTC box translates them to LUNs 4, 5, and 6. This means that, as far as Backup Exec is concerned, the robot comes first followed by its three drives.
Problem solved! I've got the thing working on its initial inventory even as I type this. Tomorrow, I start working up the backup schedule.
So -- Remember that if you have similar troubles, where Backup Exec just doesn't want to see all your drives, AND you're operating over a fiber channel link, it could easily be your LUN mapping through the fiber-to-copper bridge at the library end.
Happy tweaking.
