Intermitant Backup error

  • Run backups to a repository server with 3 strips, stats 30


    30 percent backed up.

    60 percent backed up.

    Msg 3202, Level 16, State 0, Server [SERVER NAME], Line 913

    Write on [DEVICE NAME] failed, status = 121. See the SQL Server error log for more details.

    Msg 3013, Level 16, State 1, Server "SERVER NAME", Line 913

    BACKUP DATABASE is terminating abnormally.

    This fails on one strip and on a different strip each night

    Have deleted devices and recreated

    Have dumped to a different server


  • What is the database size? Make sure you do have enough space for the backup. Generally once backup starts will completed successfully.

    "Thare are only 10 types of people in the world:
    Those who understand binary, and those who don't."

  • Check the following link

  • It is only 10GB and there is plenty of space it gets to approx 80-90% finished and then fails over

  • While running backup execute sp_who2 active for any blocking and deeply monitor server activity from which you may get some clue. Also check sql server and window error log if you can find more details

    "Thare are only 10 types of people in the world:
    Those who understand binary, and those who don't."

  • Sorry not the same error

  • Database backed up: Database:DBName, creation date(time): 2006/06/09(10:41:53), pages dumped: 1421098, first LSN: 110597:15214:2, last LSN: 110597:15725:1, number of dump devices: 4, device information: (FILE=1, TYPE=DISK: {'Z:\.....\.....\DUMPNAME1.DAT', 'Z:\.....\.....\DUMPNAME2.DAT', 'Z:\.....\.....\DUMPNAME3.DAT', 'Z:\.....\.....\DUMPNAME4.DAT'}).

    BackupMedium::ReportIoError: write failure on backup device 'Z:\.....\.....\DUMPNAME4.DAT'. Operating system error 59(An unexpected network error occurred.).

    Internal I/O request 0x07DE5A10: Op: Write, pBuffer: 0x08AE0000, Size: 131072, Position: 1722489344, UMS: Internal: 0x0, InternalHigh: 0x20000, Offset: 0x66AB1A00, OffsetHigh: 0x0, m_buf: 0x08AE0000, m_len: 131072, m_actualBytes: 0, m_errcode: 59, BackupFile: Z:\.....\.....\DUMPNAME4.DAT

    BACKUP failed to complete the command BACKUP DATABASE DBName

  • What happens if you don't stripe the backups? And it's only 10GB, why do you need to stripe it to begin with?

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  • Are these all on local drives? Or are some network?

  • Are you seeing anything extra in the SQL Server log?

  • It would appear that you are backing up to a remote drive. I would suggest backing up to a local drive first, and see if that completes successfully.

    SQL BAK Explorer - read SQL Server backup file details without SQL Server.
    Supports backup files created with SQL Server 2005 up to SQL Server 2017.

  • I would suggest looking at the logs on the server you're backing up to and also determine if there were any network issues at that time. Also, were there any other failures during this particular time on any other servers?

  • A couple of thoughts/points to explore as your backup is failing with "unexpected network error occurred" which can be caused by a wide variety of issues:

    (1) Other network activity at the time that you're trying to take your backup. It's possible that your "unexpected network error occurred" is really a timeout - what else is going on at the time you're attempting your backup?

    (2) System activity unrelated to network activity - once upon a time I ran into a server that had been schedule to reboot every evening at 10:15 PM - is your target available?

    (3) Somewhat related to #1 it's entirely possible that your network just can't handle keeping a connection open long enough to complete the operation. It's not unusual to encounter a network that just can't handle operations that take more than X seconds to complete... you may simply have a network that drops connections/packets at a level that is typically acceptable for most applications but not for yours.


  • Open the registry of the SQL Server machine and navigate to HKLM\System\CurrentControlSet\Services\lanmanworkstation\parameters

    Create a new DWORD value named SessTimeout

    Set the value to decimal 600 (hex 0x258)

    This corrected the problem for me.

    600 = 10 minutes


  • There is a possibility of the backup job running concurrently with another process, I'll suggest you use filemon or ProcessMonitor, to find out what process is obstructing the backup.

    There is the possibilty that when the backup starts, it needs to acces a file which in turn is been used by another process which you will find out with those third party applications.

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