I have a server with two storage arrays, B and D. On each of these storage arrays are several VHDX files that are mounted as drive letter E and folders inside of that letter.

I have Windows Server Backup configured for backup of B:\Virtual Disks\ (1.26TB) and D:\Virtual Disks\ (6.53TB). The backups are configured with 2 rotating sets of 1x4TB and 1x5TB USB 3.0 drives each.

My scheduled backup reports success each night, but if I assign a drive letter to the backup disks (Disk 02 and Disk 04) and navigate the backup folders, I see only 156MB of data on Disk 04 and no files on Disk 02. When I look at wbadmin, it reports 3 copies on Disk 04 totaling 0.34GB, and 0 copies and 0MB on Disk 02.

Am I missing something here?

Seems I am missing something... I just found the community addition here: Windows Server Backup Feature Overview.

So let me revise my question. How am I supposed to back up this data?

D:\Virtual Disks\Disk 1.vhdx is mounted in drive letter E.
B:\Virtual Disks\Disk 2.vhdx is mounted in folder E:\disk 2\
B:\Virtual Disks\Disk 3.vhdx is mounted in folder E:\disk 3\
B:\Virtual Disks\Disk 4.vhdx is mounted in folder E:\disk 4\

This presents remote users with only 1 drive letter (E:) with all data they need to access, despite being on multiple arrays and having multiple purposes.

Can I just run a backup of volume E:?

Hi,

Backing up of a network location (shared folders) or mapped drives is not supported in Windows Server Backup. You need to use third party tool to achieve this.

For more detailed information, please refer to the links below:

How to backup a Mapped network drive from Windows 2008 Server through windows backup
http://social.technet.microsoft.com/Forums/zh-CN/4876588e-86d6-404b-9fde-43c628556127/how-to-backup-a-mapped-network-drive-from-windows-2008-server-through-windows-backup?forum=windowsbackup

Windows Server Backup Frequently Asked Questions (FAQ)
https://social.technet.microsoft.com/wiki/contents/articles/8585.windows-server-backup-frequently-asked-questions-faq.aspx

Best Regards,

Mandy