Thank you for the explanation on what you mean by a virtual drive. (.vhd or .vhdx)
The reason why NetWorker does not back this up when you are performing a scheduled backup is because of the following reasons:
- Scheduled backups will contact the client's nsrexecd to run savefs command. This will check with Windows to see what disks are auto-mounted at boot time, and this list is then returned to NetWorker for processing.
- However, Windows "doesn’t have a built-in ability to automatic mounting of VHD files when you reboot your system." (This is stated from many different sources.) Because of this, savefs does not return the virtual drive in that list. Therefore it is not automatically backed up if you use saveset=All.
- The virtual drive is manually mounted using, for example, diskpart utility. Or can be done by the Disk Management GUI. In either case, this drive is mounted locally by the person and account that launched these utilities. This does not mean that other users or processes on that host, such as NetWorker, will see and access this virtual drive. This is likely why it fails when you try a savegroup backup of only the virtual drive. It also explains why you are successful when you start the backup manually on the client itself.
Also since this is a virtual drive, there is is actually a container file that is on the Windows file system. For example:
C:\windows\system32>diskpart
DISKPART> list vdisk
VDisk ### Disk ### State Type File
--------- -------- -------------------- --------- ----
* VDisk 0 Disk --- Added Unknown C:\temp\test-vhd.vhdx
Here, you can see that this virtual drive is actually stored on: C:\temp\test-vhd.vhdx.
So, if you backup up the C:\ drive, then this virtual drive container will also be backed up by default., although you are then limited to backing up and recovering the entire disk. And backups would only be possible if that file is not open and locked.
If you want the ability to perform file level backup and recovery, then your only option is to perform manual/local backups using the save command. You have already confirmed that this works.
