LTO Tape Drive with 2x FC ports for ControlPath failover

[rleon]

Hi all,

please refer to the following diagram.
https://imgur.com/YFdogw7

An LTO Tape Drive in an Autoloader has 2x FC ports. By default, the Robot(Media Changer) Control Path runs on port1.
With an additional software license from the Tape Autoloader vender, a "Control Path Failover" feature can be unlocked, such that if the Tape Drive's port1 fails, the Control Path will failover to run on port2 automatically.

Just want to know if Veeam Tape Servers support such Control Path failovers initialed from the Tape Drvie?
If not, then there is no point in connecting to the Tape Drive's port2, and therefore, no need to connect to SAN Switch2 using the Tape Server's SAN HBA port2.

Thanks!

[Dima P.]

Hello RLeon,

Yes, path failover is supported. Thanks!

[rleon]

Hi Dima,

The statement in the document sounds like it means failover between TapeDrives in a Tape Library with multiple TapeDrives, like this:
Drive1-Port1 - DataPath+ControlPath
Drive1-Port2 - DataPath
Drive2-Port1 - DataPath
Drive2-Port2 - DataPath
.... And then Drive1-Port1 fails, so the ControlPath fails over to Drive2-Port1, like this:
Drive1-Port1 - (failed)
Drive1-Port2 - DataPath
Drive2-Port1 - DataPath+ControlPath(moved there, so Veeam can still control the Robot/Media Changer)
Drive2-Port2 - DataPath

But, my thread question is actually asking if the following is supported by Veeam, where there is only 1 Tape Drive:
Drive1-Port1 - DataPath+ControlPath
Drive1-Port2 - DataPath
.... And then Drive1-Port1 fails, so the ControlPath fails over to Drive1-Port2, like this:
Drive1-Port1 - (failed)
Drive1-Port2 - DataPath+ControlPath

Reason for the question: Tape Library vender says their Tape Drives support this (with an addon license key), but the backup application vendor will also have to support exactly this, in order for the whole thing to work.

[lyapkost]

Hi RLeon.

This is supported. By the way, in your first example if the first path to Drive1 is failed, the second one to the Drive1 should become active control path, not the one to Drive2. Drive2 takes control only if both paths to Drive1 are failed. At least this is how it should work according documentation from HPE and what we've observed in the lab while testing. So your second exapmle is a special case of the first one.

[rleon]

Hi lyapkost,

Thanks for clarifying. Yes the vender is HPE.
Just received a copy of their compatibility matrix, it says the the thread question feature is supported by Veeam 9.5 or above. Screenshot: https://imgur.com/tckrESc
However, it is noted that this is "Driver-based" feature, meaning that you can't just use Window's native Tape Drive driver even when it works just fine, because path failover wouldn't work.
You have to install HPE's LTO7+ driver for Windows for this to actually work.
Thanks all.