Filer stops accepting new CIFS connections

Symptoms

Filer stops allowing new Common Internet File System protocol (CIFS) connections and reports the following error message:

[cifs.trace.connectionEvent:info]: CIFS: Info for client connection : Too busy to accept new client logons.

Cause

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Solution

There are several possible causes for this kind of problem:

• Too many simultaneous CIFS requests for your filer model to manage. Access to the following CIFS resources are limited by filer type and available memory:
  • Connections
  • Shares
  • Share connections
  • Open files
  • Locked files
  • Locks

  Some useful commands for troubleshooting CIFS limitation issues are:

  • cifs status
  • cifs shares
  • cifs sessions -s

  For more information, see  CIFS Access Limits By System Memory in the documentation that corresponds to your filer hardware and Data ONTAP version:

• A DNS outage. DNS outages can prevent your filer from serving CIFS connection requests. Some useful filer commands for troubleshooting DNS issues are:
  • cifs domaininfo
  • cifs testdc
  • netstat -rn
  • netstat -i
  • netstat -m
• A CPU bound filer (high processor utilization). Overloading your filer can result in CIFS access failures. Some useful commands for troubleshooting performance issues are:
  • sysstat -x 1 df -A df -i
  • netdiag -vpnda
  • ifstat -a

  Note:
  High CPU usage patterns don't always suggest a problem. When looking at the output of the systat command it's important to look at overall usage (disk, network, CPs/cache and CPU).