Windows Server 2012 R2 OS backup fails

Anthony Kirkwood

On Windows Server 2012 R2 my OS backup fails with this log:
[ERROR: 400012read volume from os client error]: Task<cfc7e9e6-8abd-48e0-81f0-605bbd2a214c> do partition backup error, partition path :C:\. os_backup_server_task/os_backup_server_task.cpp: 1501, DoOsBackup
Has anyone seen the 400012 read volume from os client error before, what are likely causes and troubleshooting steps, and which logs or diagnostic outputs should I collect?

Elias Blackwood

I’ve seen a similar 400012 error once — in my case it was caused by insufficient permissions for the backup agent. Try running the service as Administrator.

Sylas Beaumont

Is your system disk type 'dynamic'?

Anthony Kirkwood

Sylas Beaumont Yes. So it doesn't support backing up dynamic disks?

Colin

Looks like a disk/permission issue. Check OS client logs and make sure backup service can read C:.