Unable to reset password for KVM Windows VPS in SolusVM: Root/Administrator password could not be changed

Symptoms

• Unable to reset password for KVM Windows VPS at SolusVM > Virtual Servers > VPS > Root/Admin Pass:

  SVM_ERROR: Error!
  Root/Administrator password could not be changed.
  This virtual server may not be linux or Windows

• When trying to mount the VPS image with guestmount utility on the KVM node the following error is produced:

  # guestmount -a /dev/storage/kvm177_img -i --rw /home/kvm/kvm177/mnt/
  libguestfs: error: mount: mount exited with status 14: The disk contains an unclean file system (0, 0).
  Metadata kept in Windows cache, refused to mount.
  Failed to mount '/dev/sda2': Operation not permitted
  The NTFS partition is in an unsafe state. Please resume and shutdown
  Windows fully (no hibernation or fast restarting), or mount the volume
  read-only with the 'ro' mount option.

Cause

This error means that Windows filesystem keeps disk cache upon shutdown.

Resolution

1. Log in to SolusVM admin panel.
2. Disable disk cache at Virtual Servers > List virtual Servers VMID > DIsk Cache in VPS settings General tab:
   
3. After that click on Re-Configure icon and reboot VPS to apply changes.
4. For all new VPSes on that node open SolusVM > Nodes > Node Edit page, set Guest Disk Cache as None and click Update Node:
   
   

Alternatively, disk cache can be disabled inside the Windows VPS directly:

1. Connect to the VPS via VNC or RDP
2. Open command prompt
3. Execute the following command to open Device Manager:
   

   C:\> devmgmt.msc

4. Right click on Disk Drives > {Diskdrive} and click Properties
5. Choose Policies tab
6. Untick the option Enable Disk Write Caching
7. Shutdown the VPS.
8. Try to reset password from SolusVM once again.