wbadmin - access to EFI system partition fails

Sorry, but I could not change the headline in the thread were I started this issue. But error 0x807800C5 is too imprecise

https://social.technet.microsoft.com/Forums/windowsserver/en-US/79a735c1-4c50-4fa8-a945-46e25991eea9/wbadmin-failure-0x807800c5?forum=windowsbackup#47e77a02-ddb0-42dd-b33d-1475471f7bc3

So I sumarize the case:

Server 2012R2
Hypervisor with several running VM's
Up2Date 3/18/15

After weeks of succesfull backups wbadmin suddenly fails with 0x807800C5. No changes were made to the system, same backup device.

I restored a file and a VM succesfully from the backup to verify that the disk and the image is ok.

I run wbadmin from a script with:

wbadmin.exe start backup -quiet -backupTarget:f:\ -vssFull -allCritical -hyperv:vm1,vm2,vm3

Output is:

2015-03-18 23:02:17 INF > wbadmin 1.0 - Backup command-line tool
.......
2015-03-18 23:02:17 INF > The backup operation to F: is starting.
2015-03-18 23:02:17 INF > Creating a shadow copy of the volumes specified for backup...
.......
2015-03-18 23:02:17 INF > Creating a shadow copy of the volumes specified for backup...
2015-03-18 23:02:17 INF > Windows Server Backup is updating the existing backup to remove files that have
2015-03-18 23:02:17 INF > been deleted from your server since the last backup.
2015-03-18 23:02:17 INF > This might take a few minutes.
2015-03-18 23:02:17 INF > Creating a backup of volume (EFI System Partition) (100.00 MB), copied (0%).
2015-03-18 23:02:17 INF > Summary of the backup operation:
2015-03-18 23:02:17 INF > ------------------
2015-03-18 23:02:17 INF >
2015-03-18 23:02:17 INF > The backup operation stopped before completing.
2015-03-18 23:02:17 INF > The backup operation stopped before completing.
2015-03-18 23:02:17 INF > Detailed error: The specified backup disk cannot be found.

I found out that the failure only occurs if I add the -allCritical switch.

If I start the backup for drive c: with this command:
wbadmin.exe start backup -quiet -backupTarget:f:\ -include:C: -vssFull -exclude:c:\Hyper-V

everything is ok.

I can backup every virtual machine with the following command without any problem
wbadmin.exe start backup -quiet -backupTarget:f:\ -vssFull -hyperv:XYZ-DOM

Only this command fails:
wbadmin.exe start backup -quiet -backupTarget:f:\ -vssFull -allCritical

The difference is that wbadmin now tries to backup ALL partitions, also EFI & Co. So I assume that wbadmin does not have proper access to the "EFI System Partition" and that all information which one can find in the logs of the 2012 server related to that event is bullshit (Error: The specified backup disk cannot be found).

I found reports of 8.1 users rleated to similar problems (http://answers.microsoft.com/de-de/windows/forum/windows8_1-files/systemabbildsicherung-bricht-ab/f6ed5e53-829e-48be-9b47-a73f730680cc?page=1&tm=1384095732725). Could be a hint, same kernel.

But at the end: With this kind of backup you'll loose defintly the possibility of an bare-metal restore, very
unsatisfying.

Annother question: Backups with the -hyperv switch are terrible slow. The backups are written to an USB-3 disk, The xyz-Dom machine for example has two vhdx files with roundabout 700GB, more or less 350GB filled. The backup needs 12 hours!

Thank you

Klaus Deiss


March 23rd, 2015 3:25am

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