snapshot clone datastore can only be formatted not mounted

[tektotket]

What would cause the options to mount an existing vmfs 5.61 datastore to be grayed out with only the option to format available?  The datastore is on a Nimble SAN snapshot clone volume linked through iscsi.  The base parent volume for the snapshot is mounted with no problem.  Unmounting the base datastore + detaching the device before remounting the snapshot clone volume was also tried.  Getting the same result on an esxi 5.5 host not tied to vcenter and another esxi 6.0 host tied to vcenter.   HBA + VMFS rescans have been tried.  I've had no problem mounting this type of snapshot clone on these hosts in the past but it wasn't recent.  Any suggestions are appreciated.

[continuum]

Have you tried to resignature the volume from commandline ?
VMware Knowledge Base

[tektotket · Accepted solution]

here's the solution I went with:

esxcli storage vmfs snapshot list

   Volume Name: (name of datastore for parent volume of snapshot clone volume I'm trying to mount)

   VMFS UUID: **

   Can mount: false

   Reason for un-mountability: duplicate extents found

   Can resignature: false

   Reason for non-resignaturability: duplicate extents found

   Unresolved Extent Count: 3

verified hba numbering

esxcli iscsi adapter discovery sendtarget list

Adapter  Sendtarget

-------  ------------------

vmhba33  **:3260

removed all iscsi devices + sessions for multiple snapshot clone volumes associated with the same parent volume on the san array:

esxcli storage core device set --state=off -d eui.**

esxcli iscsi session remove -A vmhba33 -n iqn.**

esxcli storage core device set --state=off -d eui.**

esxcli iscsi session remove -A vmhba33 -n iqn.**

esxcli storage core device set --state=off -d eui.**

esxcli iscsi session remove -A vmhba33 -n iqn.**

esxcli storage core device set --state=off -d eui.**

esxcli iscsi session remove -A vmhba33 -n iqn.**

esxcli storage vmfs snapshot list

(no longer lists it)

re-added only the device / target for the snapshot I'm trying to mount with target + serial verified from san array:

esxcli storage core device set --state=on -d eui.**

esxcli iscsi session add -A vmhba33 -n iqn.**

The mount + resignature options are no longer grayed out in the vsphere client's Add Storage screen and the volume was successfully resignatured + mounted.

[continuum]

Thanks for posting the solution
Ulli

[tektotket]

another variation on the same problem fixed by the same steps if anyone else runs into it:

esxcli storage vmfs snapshot list

**

   Volume Name: **

   VMFS UUID: **

   Can mount: false

   Reason for un-mountability: the original volume is still online

   Can resignature: true

   Reason for non-resignaturability:

   Unresolved Extent Count: 1