Question : "The specified network name is no longer available" error on Veritas Backup Exec 10d when backing up to disk.

I am running Backup Exec 10d on a Windows 2003 network.  I have multiple Backup to Disk jobs, but different oness failing occasionally.  They always get the same error.  The lastest failure was with SQL.  My SQL server backs up to disk at 9:00 p.m. each night.  The job is less than four GBs and takes 15-20 minutes.  Some nights, though, it stops after six or seven and fails.

The error message in the job log says:

 "Storage device "SQL" reported an error on a request to write data to media.
Error reported:
The specified network name is no longer available.
V-79-57344-34036 - An unknown error has occurred.

In event viewer I can see that the SQL server is still processing the backup, but errors out because it can no longer find the Backup to Disk location.  The location itself is a large file share on a separate Windows 2003 server.  It is all new and fast hardware, with plenty of disk space.  It's as if the server simply "disappears" or loses connectivity while the backup is processing.  There are no other errors listed.  Four different backup jobs on four different servers all backup to the one B2D location.  The common thread is obviously the B2D server itself, but I can't find a cause.

Answer : "The specified network name is no longer available" error on Veritas Backup Exec 10d when backing up to disk.

This can happen if there's an incompatible setting between the NIC's and the switch. Eg enabling huge frames (>1500 bytes) on the NIC's when the switch doesn't support huge frames. Everything works fine for a while, then links drop and you get "The specified network name is no longer available"