Backup fails with "write error" in Acronis log


Backup fails and Acronis log contains "write error".

There may also be a network related error.

<event id="8" level="4" module="1" code="502" time="1317229231" message="Operation with partition '0-0' was terminated. Details: <indent>Write error. Error code: 0x70004 Tag: 0x9D2DE1F088CBC4D8 Error occurred while writing the file. Error code: 0x40003 function = "WriteFileNoCache" Tag: 0x7CEB2CDC9FB1218A The specified network name is no longer available Error code: 0xFFF0 code = 2,147,942,464 (0x80070040) Tag: 0xBD28FDBD64EDB8BC</indent>" line_tag="0xA164035B3FF39281" />


Acronis was unable to write data to the specified image location during the backup operation, or a write operation was interrupted. It may be caused by: -

  • disk error on target drive, server or NAS device
  • network instability
  • system resource / performance issues on server / NAS device hosting the image location


To isolate the cause of the problem: -

  1. ensure server or NAS device is always online and available during the backup window
  2. check if any other backup client is writing to the image location at the same time (if so, reschedule the backups in case the target server or NAS device is overloaded)
  3. check server or NAS device for any performance problems or system resource bottlenecks (e.g. high RAM or CPU usage)
  4. check network adapter drivers are up-to-date on machine you are backing up and the server or NAS device hosting the file share
  5. ensure OS/firmware is up-to-date on fie server / NAS device hosting the LAN share
  6. test the backup without any on-access AV software running on the server hosting the LAN share
  7. if the LAN share is on a computer running a Windows workstation OS, the problem may be caused by the concurrent connection limitations of this operating system. Try changing the auto-disconnect timeout as described here -  (NB - we do not recommend using a Windows workstation OS or workstation class hardware as Image Location for large or multiple backups)
  8. to further isolate the issue, test backing up to a network location on a different file server / NAS device


If you still encounter issues, please gather the following information and submit to Kaseya support: -
  1. Acronis log of failed backup (go to Backup > Backup Sets > click on 'failed' hyper-link in results column)
  2. expected size of backup
  3. image location details: -
    1. if NAS or removable storage device, specify make and model
    2. if Windows file share, collect Acronis Info report from host server
    3. network speed of server/NAS device
    4. disk hardware details (controller type, number/speed of disk units, RAID configuration)
  4. has backup been tested to other image locations? What were the results?



  • Kaseya Backup (all versions)
  • Acronis TrueImage Server (all versions)
  • Acronis Backup and Recovery (all versions)

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