Tape devices on a VMware VM

[nick_van_ogtr1]

I have a customer setup with a Dell PowerEdge R710 server and a Dell PowerVault 124T SAS autoloader.
The server has been installed as a VMware vSphere ESX host, and has the autoloader attached via a secondary SAS interface.  The network design called for a virtual Small Business Server 2008 (running on VMware vSphere), which has Backup Exec 12.5 for SBS installed.  Using SCSI pass-through the autoloader devices are connected to the VM, and these are visible to Windows, including the adapter.

I am confronted with varying scenarios whereby either one or both of the robotic and tape drive are (or go) off-line.  If everything is on-line, any single device operation causes at least the tape drive to go off-line, and sometimes the robotic as well.

The Backup Exec installation has been updated to SP3, and the latest tape device drivers have been installed.  I still have the same issue.  I have also downloaded the latest available Dell drivers and installed these, the only result of applying these is that Windows determines that the robotic device has ceased to work.  A reboot doesn't solve this.  Windows RSM services are not running.

What I am now wondering is if this is an issue with the choice for virtualisation ...

Any assistance would be greatly appreciated.

Best wishes,
Nick

[CraigV · Accepted solution]

Hi Nick,

As far as I know, this isn't a supported configuration with ESX. If your VMs are Vmotioning to another host which doesn't have the device attached, then it wouldn't exist, causing the devices to go offline as you are seeing.
It could possibly work with a SAN-attached library, but not with SCSI.
I suspect that Hyper-V has the same limitation.
Otherwise the only way around this might be to prevent your backup server from being Vmotioned at all.

Cheers!

[dpeluso]

Have you tried: http://kb.vmware.com/kb/1000024 
Also see: http://hagshur.spaces.live.com/blog/cns!2471EDB5C3481D6A!254.entry

When it comes to FC:
ESX 3.5 does not support FC connected tape devices. See  http://www.vmware.com/pdf/vi3_35/esx_3/r35/vi3_35_25_san_cfg.pdf (bottom of page 50).

[teiva-boy]

While it's been done and I've seen it mentioned in Vmware's forums, Symantec will not bless a virtualized BE server installation that attaches to physical tape...  

I'ts just too much of a hardware conundrum to troubleshoot.


Best you ask in the Vmware forums for assistance.

[nick_van_ogtr1]

Thanks to all for your replies, and apologies for my delay in responding ...

Issues relating to VMware HA (vMotion) are not present, the deployment uses VMware Essentials, so there is no vMotion'ing.  This solution was initially proposed based on the VT-d capabilities of the server, however there was never a test environment for this.  I am, of course, now concerned that we have deployed an unsupported solution.
There is also no FC at play here.

I have looked through the links provided by dpeluso, and the only thing I 'm currently pursuing here is the serialisation of the autoloader, the tape device provides it's serial number just fine.

On the positive side, the 2 devices do show up under Windows, and the tape device comes up during the BE device configuration wizard.  Strangely enough, there has been a connection of some sort to the device since the initial installation - I can see the tapes and corresponding barcode labels which have been loaded in the unit.  I'm not sure if this is simply a result of the unit passing through it's own barcode scan info, or if it was a result of a full inventory.

I will also post my question the applicable VMware forum in the hope that there is some experience along similar lines there.

Best wishes,
Nick

[CraigV]

Well, if you are able too (and if budget allows), try rolling out a stock-standard server. All you would need is a SCSI card that the device can be attached too, and the minimum amount of ram to run BEWS and the OS properly.
It is a limitation of a VM environment, and 1 which I HOPE will be sorted out by whomever has the products...we're rolling out VMware en masse shortly, and have done so on a number of sites, but we always bundle our solutions with a physical server as the virtual centre server with a SCSI card.
Maybe something to consider in the future?

PS: Which one was the solution here?

[nick_van_ogtr1]

No solution as yet, although I've just been on the line with Symantec Support.  I heard nothing regarding an unsupported solution, and in fact received a pointer in the direction of SCSI devices - apparently the SCSI device ID's used for the VM have to mirror the physical ID's.
This is explained in http://seer.entsupport.symantec.com/docs/324047.htm.

I will attempt this out of business hours today and post my results.

Best wishes,
Nick