Resolution for Windows Server Essentials 2012 r2 Client computer backup failing with ‘unknown error’ at 1%
The Eventlogs tell us pretty much nothing.
The client backup logs are in C:\ProgramData\Microsoft\Windows Server\Logs
The standard backup log (in this case backup-120517.log, just arrange by date) doesn’t tell us much and ends with:
BackupLaunchpadControl.RefreshStatus(): completed and showing status Failed and error EspCaptureFailed
ESPCapture you say? Yeh I hadn’t heard of it either.
Turns out there’s another log in the same location called espcapture.log which details where the backup client uses robocopy to copy the EFI partition to the C drive. This happens even if the EFI partition is not selected, so most likely a bug in there somewhere.
Joyfully, if there’s any corruption within the EFI parition (that you didn’t want to backup anyway) , the backup bombs out at 1%
In my case it was some corruption in Z:\EFI\dell\logs\
2017/12/05 10:51:16 ERROR 2 (0x00000002) Copying File Z:\EFI\dell\logs\ebug Mea.sur
The system cannot find the file specified.
2017/12/05 10:51:16 ERROR 123 (0x0000007B) Copying File Z:\EFI\dell\logs\à˜+Œ
The filename, directory name, or volume label syntax is incorrect.
Z: you say? – yup you can’t see it. You need to mount it first.
SELECT DISK (0 in my case, probably in yours too)
SELECT PARTITION (0 in my case, probably in yours too, the one showing as Type:system)
then you can run
CHKDSK Z: /F /R
To fix the errors.
Backup should then run.
Then tidy up.
Back into DISKPART
SELECT DISK 0
SELECT PARTITION 0
Have coffee. Hope corruption doesn’t come back. Curse MS.