Full disclosure: I have very limited experience with VTL/Tape systems in general!
We have a FAS6080 with a NetApp VTL system attached through one of the onboard inititators via our switch fabric (not direct attached point-to-point). This pre-dates me (I was not involved in the setup). It is a pretty basic setup, where the filer port and VTL port are both fabric attached, and we have a zone with both ports.
Recently we aquired a new VTL system. This was also fabric attached. I created a zone for this using the same filer initiator and the new VTL port.
On the filer, when I would query the tape stats and system, I would only see our old VTL system and drives.
etc. We have about 65 drives on the old VTL system. The command storage show mc just shows the old VTL system.
I read that I needed to cycle the port to force a re-scan. I did this today by disconnecting the port on the filer for about 2 minutes and then reconnecting. Now I see our new system, but only 5 of the old VTL's drives:
etc. You can see one of the old drives at the top of this list. There are 4 more at the end of the long list. Now the command storage show mc shows only the new VTL system.
Is there a limitation on drives per initiator? Should we be connecting each tape system through its own initiator on the filer instead of sharing them through one? Is there some other piece of the puzzle that I'm missing?
I put the new VTL on a different initiator and could see both media changers simultaneously, but still not all of the drives.
Based on our reading and chatting with support, it appears there is a limit of 64 tape drives per filer. I find it a little strange that a system we have attached to our old VTL actually does show exactly 64 drives, but with the new system attached with the old, I'm seeing 66 drives.
I think this is a hard limit that is not configurable.