Create Instance failed (Failed to create server volumes)

[ThorstenBolz]

Hello together,

i published my alltera mpb as storage system in essentilas manager. it is showing ok, but when i want to create an instance, following error:

Some hints for me?

[CalvinZito]

I have a Copilot notebook based on the software documentation. Here's what it says:

The error message suggests that VM Essentials is able to communicate with the Alletra MP array, but it cannot find a valid multipath device for the presented LUN on the HVM host:

"Failed to create server volumes: Multipath device for volume WWN ... on host hpmorpheus1 is null"

A few things I'd check:

1. Verify the LUN is actually presented to the host
   • On the Alletra MP side, confirm the volume was mapped to the host set used by your HVM cluster.
   • Make sure the host WWNs/IQNs are correctly registered.
2. Check multipath on the HVM host
   • SSH to hpmorpheus1 and verify the volume is visible:
     1  multipath -ll
   • The volume WWN shown in the error should appear as a multipath device. If it doesn't, the host is not seeing the LUN correctly.
3. Validate host multipath configuration
   • For Alletra MP, the documentation recommends:

     defaults {
         find_multipaths yes
         user_friendly_names no
     }
     

   • Confirm the configuration is present on all cluster hosts and restart multipathd if changes were made. 
4. Confirm all storage paths are online
   • If using iSCSI, verify sessions are established.
   • If using FC, verify zoning and that all expected paths are visible from the host.
5. Rescan storage and retry
   • After confirming presentation and connectivity, rescan storage on the host and verify the WWN appears in multipath -ll before trying the deployment again.

Could you share:

• Whether you're using iSCSI or Fibre Channel?
• The output of multipath -ll on hpmorpheus1?
• Whether the datastore was created successfully and shows as Healthy in the cluster storage view?

That should help narrow down whether this is a presentation issue, a multipath configuration issue, or a host discovery issue.

NOTE: the answer is based on pages 400-487 in the v9.0.1 version of the VM Essentials software documentation. Please let me know if the answer helps you move forward.