Windows Disks go Offline After Reboot

Problem

Volumes attached to a running Windows guest becomes offline after reboot. The following warning is observed in the Windows disk management utility.

xxxxxxxxxx

"The disk is offline because of policy set by an administrator"

Environment

• Platform9 Managed OpenStack - All versions.
• Nova

Cause

SAN policy has been introduced in Windows to protect shared disks accessed by multiple servers. By default, Windows machines will have the SAN policy set to be " Offline Shared", thus irrespective of the libvirt/ qemu or hardware version you may see this issue.

Resolution

1. Open a command prompt from within the virtual machine.
2. Run the diskpart utility by running the command:

xxxxxxxxxx

diskpart.exe

3. To display the SAN policy, run the command:

xxxxxxxxxx

diskpart> sanSAN Policy: Offline Shared

4. Change the SAN policy to be online with the command:

xxxxxxxxxx

diskpart> san policy=OnlineAllDiskpart successfully changed the SAN policy for the current operating system.

5. To get summary information about each disk, run the command:

diskpart>list diskDisk Status Size Free Dyn Gpt--------------- ------------------ ----------- ----------Disk 0 Online 40 GB 0 B*Disk 1 Offline 60 GB 1024 KB

6. Select Disk 1 (currently offline disk) with the command:

xxxxxxxxxx

diskpart>select disk 1Disk 1 is now the selected disk

7. Clear the read-only attribute for Disk 1 with the command:

diskpart>attributes disk clear readonlydisk attributes cleared successfullydiskpart>attributes diskcurrent read-only state: noboot disk: nopagefile disk: nohibernation file disk: nocrashdump disk: noclustered disk: no

8. Bring Disk 1 online with the command:

xxxxxxxxxx

diskpart>online diskdiskpart successfully onlined the selected disk