Challenge
The following entry can be seen in the log file:
BackupDisk failed
Client error: Insufficient system resources exist to complete the requested service
Failed to write data to the file [\\xxx.xx.xxx.xxx\xxx\xxx\veeambackup.vbk].
Cause
The error is coming from the Windows server, on which Veeam Backup and Replication is installed.
Solution
To resolve this issue, refer to the Microsoft KB that provides instruction on how to address: http://support.microsoft.com/kb/304101