Product Documentation

CIFS Management Summary

Dec 09, 2014
  • CIFS acceleration provides significant improvement even at relatively short link distances.
  • CIFS acceleration begins when a file system is first accessed by the client. If acceleration is enabled with the file server and client already up and running, no acceleration occurs for many minutes, until the preexisting CIFS connections are fully closed. CIFS connections are very persistent and last a long time before closing themselves, even when idle. This behavior is annoying during test, but has little importance in normal deployment.
  • Dismounting and remounting a file system in Windows does not close the CIFS connections, because Windows does not really dismount the file system fully. Rebooting the client or server works. For a less invasive measure, use the NET USE devicename /DELETE command from the Windows command line to fully dismount the volume. In Linux, smbmount and umount fully dismount the volume.
  • Disabling and then reenabling CIFS read and write optimizations on the appliance raises similar issues. Existing connections do not become accelerated when CIFS is enabled, and the number of “protocol errors detected” on the Monitoring: Filesystem (CIFS/SMB) page increases briefly.
  • CIFS statistics can be confusing, because only the appliance farthest from the fileserver reports CIFS acceleration with full statistics. The other appliance sees it as ordinary acceleration.
  • CIFS acceleration is not supported in proxy mode.
  • If CIFS acceleration does not take place with a Windows server, check the server’s security settings.