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.
- 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.
- 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.
- 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.