I recently started getting these failures on a server I manage. The error in Windows Backup states:

Creation of the shared protection point timed out. The shared protection point operation failed with error 0x81000101.

The event log had this:

The backup operation that started at '‎2014‎-‎05‎-‎09T02:00:32.813000000Z' has failed because the Volume Shadow Copy Service operation to create a shadow copy of the volumes being backed up failed with following error code '2155348001'. Please review the event details for a solution, and then rerun the backup operation once the issue is resolved.

I was at my wits end with this as a full backup would work. Eventually Google helped me... The solution was to:

1. Open regedit.exe
2. Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SPP
3. Add a new 32-bit DWORD key called CreateTimeout with the hex value b71b00 (20 minutes)
4. Retry the backup.

This happens because it could be taking longer than the maximum allowed duration of 10 minutes to create the shared protection point when you have lots of data and many disks, and then the operation times out.