Article number
Affected Versions
Source Hypervisor
Target Hypervisor

VPG0043 – The Microsoft default SAN policy might cause VM ‘{VM_name}’ (VPG ‘{VPG_name}’) volumes to become offline upon recovery

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Root Cause

Versions of Windows above 2003 have a default diskpart policy that is set to "Offline Shared". This causes the disk to be mounted in offline state.


An alert may be received: The Microsoft default SAN policy might cause VM '{VM_name}' (VPG '{VPG_name}') volumes to become offline upon recovery.

When performing a Zerto Move or Failover operation, one of the recovery disks for a protected VM fails to mount on the recovered VM on the DR site. The disk comes up in offline mode and has to be manually brought online. This issue occurs with disks using the PVSCSI driver.


Fix (For AWS only as the recovery site):
This issue is resolved in Zerto 8.0

** Important note regarding this fix **: Note that this fix does not alter the SAN policy in any way. The SAN policy only affects newly attached disks, and in the case of a failover, the disks are already attached. Whatever setting the SAN policy was set to on the protected site will carry over to the recovery site on failover. What this fix does is set the script to make all current disks online after the first reboot after a failover, regardless of the SAN policy setting. If a user were to manually attach a new disk after failover, this new disk would follow the SAN policy setting.

Workaround (for all other hypervisors and versions):
The resolution requires setting the diskpart policy to "OnlineAll" using the following steps:

1) Open the command prompt on the relevant vm.
2) Launch "diskpart"
3) Type "san" to confirm the server is set to "Offline Shared"
4) Typed "san policy=OnlineAll"

If the user is using Powershell CMDlets:
To login to the VM :
Enter-PSSession "VMname"
To check the storage Policy :
Get-StorageSetting | Select-Object NewDiskPolicy
To set the disk to Online :
Set-StorageSetting -NewDiskPolicy OnlineAll

For more information see the following external KBs: