How to check write cache disk usage from XenServer Hypervisor

How to check Write Cache Disk usage from XenServer hypervisor...

Citrix Hypervisor 8.2 : xe-toolstack-restart causes the PVS VMs to go into PowerState Unknown.

PVS VMs may showPowerState Unknown inCitrix Studio when the toolstack is restarted on the XenServer Hypervisor hosting the VMs. Currently logged in sessions will be unaffected however any new user trying to log may encounter an error as the site is unable to determine if any VMs are powered on an...