Unable to mount a VMFS volume to an ESXi Host

Products

• VMware vSphere ESXi 7.0

Issue/Introduction

When trying to mount a datastore to an ESXi Host you encounter the following problem.

'An unresolved VMFS volume with signature naa.################################:# has been detected on disk'.

The option to mount the datastore with 'Assign new signature' and or 'Keep existing signature' are both greyed-out.

The only available option is to 'Format the disk'.

Reason for non-resignaturability: duplicate extents found - see screenshot below.

 

Running the command 'esxcfg-volume -l' gives the following output.

VMFS UUID/label: ########-########-####-########/datastorename
Can mount: No (duplicate extents found)
Can resignature: No (duplicate extents found)
Extent name: eui.################################:1 range: 0 - ########(MB)
Extent name: eui.################################:1 range: 0 - ########(MB)

 

Cause

There are 2 snapshots of the same datastore presented to the Host.

Resolution

1. Detach one of the duplicate snapshot LUNs presented to the Host
2. Re-signature the remaining snapshot LUN presented to the Host

esxcli storage vmfs snapshot resignature -u "########-########-####-############"

Additional Information

Troubleshooting LUNs detected as snapshot LUNs in vSphere