After 20H2 update on Windows Pro, Hyper-V Virtual Machine Management service Account does not have permission to open attachment

[Heretic Wild]

I have a single Virtual Machine running on a dedicated encrypted hard drive.


After upgrading from 1909 to 20H2, I can no longer start my VM.


Error is:

'SFCC': 80070005 Account does not have permission to open attachment '\\?\scsi#disk&ven_ct500mx5&prod_00ssd1#4&1e9352cd&0&000300#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}'. Error: 'Access is denied.' (7864368). (Virtual machine ID 57221546-1FBD-4F26-9142-FAEAF0C4E687)

Tried granting access with icacls, to no avail.

Tried in elevated command prompt and in Powershell.

No luck.


C:\WINDOWS\system32>icacls "\\?\scsi#disk&ven_ct500mx5&prod_00ssd1#4&1e9352cd&0&000300#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}" /grant "NT VIRTUAL MACHINE\57221546-1fbd-4f26-9142-faeaf0c4e687":F

\\?\scsi#disk&ven_ct500mx5&prod_00ssd1#4&1e9352cd&0&000300#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}: Incorrect function.

Successfully processed 0 files; Failed processing 1 files



C:\WINDOWS\system32>icacls "..\scsi#disk&ven_ct500mx5&prod_00ssd1#4&1e9352cd&0&000300#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}" /grant "NT VIRTUAL MACHINE\57221546-1fbd-4f26-9142-faeaf0c4e687":F

..\scsi#disk&ven_ct500mx5&prod_00ssd1#4&1e9352cd&0&000300#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}: The system cannot find the file specified.

Successfully processed 0 files; Failed processing 1 files


PS C:\WINDOWS\system32> $VM = Get-VM SFCC

PS C:\WINDOWS\system32> Foreach ($v in $VM) {

>> $Disks = Get-VMHardDiskDrive $v

>> $Permissions = $v.VMId.Guid + ":F"

>>

>> Foreach ($d in $Disks) {

>> icacls $d.path /grant $Permissions

>> }

>> }

Disk 1 465.76 GB Bus 0 Lun 0 Target 3: The system cannot find the file specified.

Successfully processed 0 files; Failed processing 1 files


I guess I can't use icacls for a physical disk - only for a virtual disk (file)?

So, how do I grant access to the Hyper-V Virtual Machine Management service Account so it will start my VM?

Continue reading...