I was told a virtual machine an a cluster node was acting strange so i decided to investigate a bit further…

i turned off the virtual machine to modify some settings and when i restarted it could not start!

the first message i got was essential General Access is Denied…

this turned out to be a permissions problem but on the access list on the VHD NOT THE NTFS permissions

S:\>icacls S:\Clusterstorage\Volume1\VMSTORE\ /T /grant “NT VIRTUAL MACHINE\Machine GUID“:(F)

this commands sorted this problem out…

Once i tried to start the virtual machine again i got the lovely “A Device to the system is not functioning”

i hate this message personally but its surprisingly easy to sort (most of the time)

Simply check your antivirus has VHD exclusions…. a simple test is to disable the antivirus on the platform you are trying to start the vhd (ensure if it is on a cluster that you also move the volume to the node you are turning the antivirus off otherwise you still get the error)

once you have verified then stop the antivirus on all nodes configure your exclusions then start your antivirus and start you VM’s


Good Luck! 🙂