VMs not in Write-Back mode after VMware cluster assignment is changed for the host(s)
If the VMs are in Write-Through mode when they should have been in Write-Back mode, please check the cluster name assigned to the host as shown in VirtuCache. The only way to check the cluster name in VirtuCache is by running the list-ssd command (if you are using SSD as cache device) or get-mem-cache command (if you are using memory as cache device) using VirtuCache CLI (type vnxcli at ESXi CLI). If the hosts that are supposed to be in the same ESXi cluster show different cluster names in VirtuCache, then VirtuCache will not be able to create write replicas across hosts, as a result, the VMs won’t move to Write-Back mode.
One common reason for this is if the hosts that run VirtuCache are reassigned from other ESXi clusters.
To correct this issue:
1) Stop caching on all the hosts in the VMware cluster where hosts show a different cluster name than what the ESXi cluster name should be.
2) De-provision SSD on all the hosts in those clusters by clicking on the ‘Stop Caching’ (red button) on the Hosts tab.
3) Reattach the SSD to VirtuCache from the Hosts tab in VirtuCache manager GUI
The above process will correct the cluster name in VirtuCache at the host level.