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What is the "_ocs_vserver" workload in qos statistics?

Last Updated:

Applies to

  • ONTAP 9
  • ONTAP Copy Subsystem (OCS)


  • _ocs_vserver is a QoS internal workload ID for Copy Offload, known as VAAI, ODX
  • This may be identified from a Performance case, or from the command qos statistics workload resource cpu show.
  • Example:

cluster1::> qos statistics workload resource cpu show -node nodeB
Workload            ID   CPU
--------------- ------ -----
-total- (100%)       -   30%
_ocs_vserver_a3      -   20%
vs0-wid101         101   12%
file-1-wid121      121   10%
vol0-wid1002      1002    8%
_DEDUP               -    7%
-total- (100%)       -   30%
vs0-wid101         101   12%
file-1-wid121      121   10%
_ocs_vserver_a3      -   10%
vol0-wid1002      1002    8%
_DEDUP               -    7%

  • Offloading the reading of data from a source and the writing to a destination via the use of an in-band SCSI command known as EXTENDED_COPY
    • This mainly includes Storage vMotions (VMware initiated data migration)
  • For Copy Offload work, OCS creates a default QoS workload per destination vserver
  • These workloads follow a well-defined naming scheme; each workload name is of the form _ocs_vserver_<vserver UUID>, where the vserver ID is the UUID of the destination vserver.


  • The following solution involves running diagnostic commands
  • Please contact NetApp Technical Support if you have any concerns with implementing this solutio
  • While the QoS interfaces do not provide the ability to manage those workloads' policies, there is a diag-mode command, copy-offload modify, that can set a throttle on misbehaving copy-offload workloads.
    • Example:
      • ::> set diag
      • ::*> copy-offload modify -throttle {<integer>[KB|MB|GB|TB|PB]}
  • Copy offload may also be disabled:
    • CIFS:
      • ::> set advanced
      • ::*> cifs options modify -vserver <vserver_name> -is-copy-offload-direct-copy-enabled false
      • Note: This will require moving the data LIF or Windows clients to reconnect to take effect
    • NFS and FCP/iSCSI:
      • ::*> set diag
      • ::*> copy-offload modify ?
          [[-vserver] <vserver name>]                       *Vserver Name (default: svm0)
          [[-nfs] {enabled|disabled}]                       *NFS Copy-Offload
          [ -scsi {enabled|disabled} ]                      *SCSI Copy-Offload
      • See man copy-offload modify for more information
      • Note: Disabling for CIFS is non-disruptive, but SAN requires disabling and enabling the LUN

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