VMs not in Write-Back mode because of ‘LUN not claimed’ message

If some VMs are not in Write-Back operational state when caching policy is set as ‘Write-Back 1 Replica’, it could be because of VirtuCache is not claiming the LUN when it was installed.

You can verify this symptom by issuing ‘list-vms’ command in vnxcli (type vnxcli in ESXi CLI) for the ESXI host that hosts the VM and if you see ‘LUN not claimed’ message for the VMs that have this issue.
This is only applicable if VM/datastore policy is Write-Back.

To resolve this issue, you will have to reload VirtuCache on all hosts:
– Pause/Stop caching (using GUI) on all ESX hosts, one by one
– After caching has been paused on all hosts, do the following for each host
– Put host in maintenance mode
– Unload VirtuCache driver by typing the below command in ESXi CLI
/etc/init.d/vnx2.sh stop
– Reload VirtuCache driver by typing the below command in ESXi CLI
/etc/init.d/vnx2.sh start
– Take host out of maintenance mode
– Do the above for other hosts one at a time