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Verifying the existence of two paths: storage show disk command

You should verify that your V-Series system is configured with two paths to an array LUN so that there is a secondary path in case the primary path fails or is taken offline.

Steps

  1. Enter the following command to show the primary and secondary paths to LUNs: storage show disk -p all
    The system displays information similar to the following:
    PRIMARY 	PORT             SECONDARY  PORT           SHELF BAY ADAPTER
    -------------------- ---- ------------------------- ---- ---
    vnmc4500s32:4.127L1    -    vnmc4500s33:19.127L1   -     -    -   0a
    vnmc4500s32:4.127L12   -    vnmc4500s33:19.127L12  -     -    -   0a
    vnmc4500s33:19.127L2   -    vnmc4500s32:4.127L2    -     -    -   0c
    vnmc4500s33:19.127L13  -    vnmc4500s32:4.127L13   -     -    -   0c
    Note: When you use the all variable, adapters are displayed, but unassigned LUNs are not visible.
  2. Determine whether a primary path and a secondary path to the array LUNs are shown.
    If you do not see a primary and secondary path, check zoning, host group configuration, and cabling.
    Note: Do not continue with testing until you see two paths.
  3. Look at the adapters shown to see whether all paths are on a single adapter.
    If you see both paths through one port (for example, both paths through the 0c port), this is an indication that the back-end zoning is redundantly crossed. This is not a supported configuration.
    Note: Data ONTAP changes the path to array LUNs, as necessary, for load balancing. Therefore, the primary and secondary paths for a given array LUN can change when the storage show disk command is issued at different times.