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How to check if SMB multichannel is being used

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ontap-9
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Applies to

  • ONTAP 9
  • SMB Multichannel
  • CIFS Server

Answer

  1. Confirm SMB Multichannel is enabled and corresponding parameters match default or desired settings.

cluster1::*> vserver cifs options show -fields is-multichannel-enabled,max-connections-per-session,max-lifs-per-session
vserver       is-multichannel-enabled max-connections-per-session max-lifs-per-session
------------- ----------------------- --------------------------- --------------------
svm1_cluster1 true                    32                          256

  1. Because a given CIFS session is visible to only one node, the SMB3 client can be allowed to bind the session to the connections that are established to the LIFs hosted on only that node. When the SMB3 client queries for a list of interfaces, the node returns only the locally hosted LIFs.  Confirm two or more CIFS LIFs exist per node.

cluster1::> network interface show -vserver svm1_cluster1 -data-protocol *cifs* -curr-node cluster1-01
            Logical    Status     Network            Current       Current Is
Vserver     Interface  Admin/Oper Address/Mask       Node          Port    Home
----------- ---------- ---------- ------------------ ------------- ------- ----
svm1_cluster1
            svm1_data_lif1
                         up/up    192.168.0.131/24   cluster1-01   e0c     true
            svm1_data_lif2
                         up/up    192.168.0.132/24   cluster1-01   e0d     true
2 entries were displayed.

  1. Display the client CIFS session.  Include optional parameters to filter the output.

cluster1::> vserver cifs session show
 
Node:    cluster1-01
Vserver: svm1_cluster1
Connection Session                                        Open         Idle      Connection
ID         ID      Workstation      Windows User         Files         Time           Count
---------- ------- ---------------- ---------------- --------- ------------ ---------------
3959579707 6796776262632210435                                       4m 51s               2
                   192.168.0.5      DEMO\                    3
                                    Administrator

  1. Refer to Configure SMB Multichannel for performance and redundancy for the expected number of simultaneous connections in an SMB session.
  2. Display the connections for the associated Session ID.

cluster1::> vserver cifs connection show -session-id 6796776262632210435
Node:    cluster1-01
Vserver: svm1_cluster1
Connection Session                               Workstation
ID         IDs                   Workstation IP  Port        LIF IP
---------- --------------------- --------------- ----------- ---------------
3959579707 6796776262632210435   192.168.0.5     50602       192.168.0.131
3959579708 6796776262632210435   192.168.0.5     50603       192.168.0.132
2 entries were displayed.

  1. If the number of connections per session match with what was found in the reference document in step 4, SMB Multichannel is in use by the client.  If not, refer to the links in the Additional Information section for troubleshooting.

Additional Information

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.