Skip to main content
NetApp Knowledge Base

What are the CIFS values to mitigate client malfunction?

Views:
6,203
Visibility:
Public
Votes:
6
Category:
ontap-9
Specialty:
nas
Last Updated:

Applies to

  • ONTAP 9
  • CIFS

Answer

The purpose of limits is the lower the chance of a client overwhelming a node in the cluster.

Examples:

EMS message EMS reference Knowledge Base article

Nblade.cifsMaxSessPerUsrConn

nblade.cifsmaxsessperusrconn events (netapp.com) CIFS shares access may fail and EMS displays error "cifsMaxSessPerUsrConn"
Nblade.cifsSameTreePerSess nblade.cifssametreepersess events (netapp.com)  
Nblade.cifsMaxOpenSameFile nblade.cifsmaxopensamefile events (netapp.com) Error: Nblade.cifsMaxOpenSameFile when CIFS Clients attempt to access files in ONTAP
Nblade.cifsMaxWatchesPerTree  nblade.cifsmaxwatchespertree events (netapp.com)  

Note: Every cluster is different and may require different maximums due to physical constraints. Testing is required.

Additional Information

clipboard_ecbea7202341fc992178cfb0e992734d8.png

  • The default values for these fields were increased in ONTAP 9.3.
  • ONTAP systems upgraded to ONTAP 9.3+ may retain their original default values, though these values can still be modified as necessary
  • Increasing a value is unlikely to cause any issue and should be considered when undesirable behaviour occurs as per above references
  • This may be expected behaviour for services establishing a CIFS session on behalf of multiple users:

Examples:

  • Xen server,
  • IIS server or other web servers

Note: If not expected, client-side investigation with OS/Application vendor needs to be performed

  • Recommendations should come from the Client OS/Application Vendor.
  • Client OS/Application vendor provides no guidance on these values:
    • If there is an expectation that the default value will be exceeded in a natural manner, but there is uncertainty about how the natural behavior will go, then testing higher values will be necessary.
    • There is no perfect method of determining a perfect number to set the value to.
  • One method of testing might be doubling the value, if the error returns, double again, etc.
  • Another method is more slowly increasing the value until the error goes away. (assuming behavior of the OS/application vendor is expected)
NetApp provides no representations or warranties regarding the accuracy or reliability or serviceability of any information or recommendations provided in this publication or with respect to any results that may be obtained by the use of the information or observance of any recommendations provided herein. The information in this document is distributed AS IS and the use of this information or the implementation of any recommendations or techniques herein is a customer's responsibility and depends on the customer's ability to evaluate and integrate them into the customer's operational environment. This document and the information contained herein may be used solely in connection with the NetApp products discussed in this document.
Scan to view the article on your device