[SOLVED] Raw device mapping for MS clusters

[RBretzel]

Hi,
for the supported operation of an MS cluster as a VM, the "Cluster validation test" must be successfully completed.
To pass this test, the disk must be mapped into the VM as a raw device (passthrough disk).
What possibilities are there to implement this?
How did you solve this or is there already an article with the solution that I can't find?

Regards
Rainer

 

[Neobin]

Not sure, if this is what you mean:
https://pve.proxmox.com/wiki/Passthrough_Physical_Disk_to_Virtual_Machine_(VM)

 

[RBretzel]

Hi, thanks for the link, this works with internal disk and single iSCSI disk as I had hoped.
With the iSCSI multipath disk I could only mount one disk (/dev/disk/by-id/scsi-XXX), if I want to mount the second path it replaces the first disk, because both disks are listed as sdX in the system.

Do you have a suggestion or idea how I can realize this?
I am thankful for any ideas!

 

[RBretzel]

Hi,
I have found the solution and would like to share it with you.

To add a pass-through physical hard disk to the virtual machine or hot-plug/add a physical device as a new virtual SCSI hard disk, you need to execute the “dm-devcie” using the multipath command.

#multipaht -ll


Then make the disk available to the VM as a new SCSI device

#pm set VM-ID -scsi<No> /dev/dm-<No>

best
Rainer

 

[bbgeek17]

Hi Rainer,

This technique is incorrect from the perspective of the Microsoft Cluster Validation tests. Specifically, the persistent reservations handling needs to be multi-path aware since reservations are scoped to the independent SCSI ITL nexuses. In this case, QEMU abstracts the presence of multipathing.

I don't recommend moving these machines around in a Proxmox cluster. This sort of deployment can likely lead to data corruption.
Good Luck!

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