Error: Client error The requested operation could not be completed due to a file system limitation Failed to flush file buffers. File: Filename.vbk
Veeam is not able to write any data to the affected file because of a NTFS limitation.
Manual un-deduplication (Expand-DedupFile) of the this file also fails with the same error.
Backup repository must be located on a volume formatted with the large FRS using the command
Format <Drive:> /FS:NTFS /L
For Windows Server 2008(R2) please refer to Microsoft KB for a detailed description of the issue:http://support.microsoft.com/kb/967351
This issue is resolved in Windows Server 2012(R2), however formatting with the large FRS using the command “Format <Drive:> /FS:NTFS /L is still needed.
Important: the command Format <Drive:> /FS:NTFS /L erases all data from the drive.
Additional information regarding suggested configuration of Server 2012 dedupe for backup storage can be found in this article: http://technet.microsoft.com/en-us/library/dn891438.aspx
Depending on the total size of the volume to be formatted you may have to set the cluster size during the format process. Please reference this article to determine which cluster size is needed. http://support.microsoft.com/kb/140365/
Forr more information related to this issue please see this forum post: http://forums.veeam.com/veeam-backup-replication-f2/error-related-to-file-system-limitation-t21448.html
Please note: reformating the volume with /L flag usually helps, but you can still get the same error message later, you can still hit limitation and 4096 Bytes Per FileRecord Segment will not be enough