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Selective LUN Map

Selective LUN Map (SLM) reduces the number of paths from the host to the LUN. With SLM, when a new LUN map is created, the LUN is accessible only through paths on the node owning the LUN and its HA partner.

SLM enables management of a single igroup per host and also supports nondisruptive LUN move operations that do not require portset manipulation or LUN remapping.

Portsets can be used with SLM just as in previous versions of ONTAP to further restrict access of certain targets to certain initiators. When using SLM with portsets, LUNs will be accessible on the set of LIFs in the portset on the node that owns the LUN and on that node's HA partner.

SLM is enabled by default on all new LUN maps.

  • How to determine whether SLM is enabled on a LUN map
    If your environment has a combination of LUNs created in ONTAP and LUNs transitioned from previous versions, you might need to determine whether Selective LUN Map (SLM) is enabled on a specific LUN.
  • Creating port sets and binding igroups to port sets
    In addition to using Selective LUN Map (SLM), you can create a port set and bind the port set to an igroup to further limit which LIFs can be used by an initiator to access a LUN. If you do not bind a port set to an igroup, then all of the initiators in the igroup can access mapped LUNs through all of the LIFs on the node owning the LUN and the owning node's HA partner.
  • Modifying the SLM reporting-nodes list
    If you are moving a LUN or a volume containing LUNs to another high availability (HA) pair within the same cluster, you should modify the Selective LUN Map (SLM) reporting-nodes list before initiating the move. This ensures that active, optimized LUN paths are maintained.
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