Hi! We installed new tape library HP MSL6480, configured partition on it and LTO7+ Control Path Failover/Data Path Failover. Library connected via FC to SAN Fabrics. In BE servers Device Manager I see 4 medium changers (4 paths for changer) and 28 drives (14 drives with 2 path each). How can I configure BE 16 to use only Primary Device and not to use Alternative.
List of changers:
d:\2>query_drvr -d CHANGER0
Device at selected path: HP MSL6480 FW: 5.30 SN: ...
Driver version: 126.96.36.199x64
Changer0 HP MSL6480 5.30 SN: ...
Primary (Enabled) OS Addr: Scsi6:0:0:1 WWPN: 5001:4380:36b9:fb64
Alternate (Enabled) OS Addr: Scsi6:0:1:1 WWPN: 5001:4380:36b9:fb6e
Alternate (Enabled) OS Addr: Scsi7:0:0:1 WWPN: 5001:4380:36b9:fb65
Alternate (Enabled) OS Addr: Scsi7:0:1:1 WWPN: 5001:4380:36b9:fb6f
Normally with multi-path setups BE sees what the OS presents as active and what the OS sees as active vs passive depends on how you have configured your multi-path software.
Basically it can't be configured in a teaming mode (if such a thing is possible) it must be configured in a failover mode.
I am not aware we have seen issues like this with multi-pathing tape devices, but, as a comparitive example, we did get a customer do something similar with multi-pathing the disk storage used by VMware datastores (and presenting to the BE server over multi-path for SAN transport) - each datastore volume was visible twice in the Windows Disk manager and it messed up how BE worked with the backup and retore process. It was only fixed when the customer made sure that his multi-path software was setup so that Disk manager only saw each volume once.
Ok sounds like BE is seeing what the OS is presenting - so exactly the same as the multi-path problem I described and I suspect you will have to find a configuation where it is not seen that way in Device Manager. BE typically does not have direct support for multi-device connections, we do just rely on how the operating system presents the connections to us.
You might want to give it 24hours on these forums though - as having global membership, you might find a community member from another timezone with experience or knowledge on the exact same scenario can contribute
It works, but not so as I expected. With this amount of devices in device manager BE on startup generates too many errors on devices with alternative path (for 3 changers and 14 drives). But devices in primary state works good.
For now, I opened support case on HP and then, if needed, I'll open case on Veritas.
Basically, MSL6480 not supporting MPIO. It support Path Failover, which is some kind of MPIO, but not exactly.
HP L1 support can't help us, so they escalated our case to L2. I collected support ticket on Tape Library, they analyzing it...
Hello. We received a response from HP L3 Support. For LTO7+ Path Failover, such number of devices in device manager is normal, and management of these devices must deal with backup software. Unfortunately, BE does not currently support LTO7+ Path Failover. Such support is only available for NetBack. Therefore, it only remains to use the 1 path drives and changer. Maybe in next releases Veritas add support of LTO7+ Path Failover to Backup Exec.