Windows Server: how to fix Virtual Disk not attached on reboot

In my lab environment I had a problem with Storage Pool, based on Windows Server 2019, because after every restart one of the volume was not available automatically. The result is like figure 1.

Figure 1 – Volume Unknown

As you can see, is possible attach the volume but this means that virtual machines are not present, so there’s no auto-start.

If you try to check the volume status, with PowerShell cmdlet Get-VirtualDisk -FriendlyName “Volume Hybrid”, the result is like figure 2.

Figure 2 – Manual Attach

The status IsManualAttach = True means that the volume must be mounted manually. To fix this is necessary run this cmdlet Get-VirtualDisk -FriendlyName “Volume Hybrid” | Set-VirtualDisk –IsManualAttach $False.

If you run again the check, the result is like figure 3.

Figure 3 – Manual Attach Disabled

Now you can reboot your server and check the result. Very easy!