"Assign a new signature" and "Keep existing signature" options greyed out

Products

• VMware vSphere ESXi

Issue/Introduction

• Unable to select "Assign a new signature" and "Keep existing signature" options while mounting the datastore.
  Only the "Format the disk" option is available.

•  Re-signaturing a snapshot LUN via "Add Storage" might also report the same issue.

Environment

VMware vSphere ESXi 8.0

Cause

This issue is reported if one of the extent or the backing device of the datastore goes missing in an multi-extent datastore configuration.

'esxcli storage vmfs snapshot list' from the ESXi shows the reason for un-mountability as some extents missing.

[root:~] esxcli storage vmfs snapshot list
#####-######-####-########:
Volume Name: ########
VMFS UUID: #####-######-####-#######
Can mount: false
Reason for un-mountability: some extents missing
Can resignature: false
Reason for non-resignaturability: some extents missing
Unresolved Extent Count: #

Note:
This issue can also occur in multi-extent datastore if storage-level replication is incomplete. If one LUN is replicated and presented to the target ESXi host, but another required extent is left behind, the host will detect the partial datastore as a snapshot. However, the resignature operation will fail because an active extent is missing.

   

Resolution

• Present all the backing device for the multi-extent datastore is presented on the host.

Additional Information

Troubleshooting LUNs detected as snapshot LUNs in vSphere