os/400 i5os IBM i remove stale LUN paths

This may need to happen if you remove/re-add NPIV mapping, if SAN topology changes, or if you have removed maps, ports, cables, or entire LUNs.

1. Change the configuration on the array to remove the extra ports, etc.
2. Physically remove any fibre cables if needed.
3. IPL the server.
4. Run the STRSST command., then Press ENTER
5. Option 1, Start a service tool, then Press ENTER
6. Option 4, Display/Alter/Dump, then Press ENTER
7. Option 1, Display/Alter storage, then Press ENTER
8. Option 2, Licensed Internal Code (LIC) data, then Press ENTER
9. Option 14, Advanced analysis (scroll down to see this option), then Press ENTER
a. Scroll down and type 1 by MULTIPATHRESETTER, then press ENTER
b. Options, -RESETMP -ALL -CONFIRM, then press ENTER

DISPLAY/ALTER/DUMP
Running macro: MULTIPATHRESETTER -CONFIRM -ALL
Reset the paths for Multiple Connections

********************************************************************
***CONFIRM RESET MULTIPATH UNIT PATHSTO NUMBER CURRENTLY ENLISTED***
********************************************************************

This service function should be run only under the direction of the
IBM Hardware Service Support.

You have selected to reset the number of paths on a multipath unit
to equal the number of paths that have currently enlisted.

Attempting to reset path for resource name: DMP004
Attempting to reset path for resource name: DMP075
...

*** Your request completed successfully ***
The number of paths connected to your multipath unit have been reset
to match the number of paths that are currently enlisted.
NOTE: If ALL paths are removed, the disk resource name will still show as DMPxxx rather than DDxxxx.

NOTE: DMPxxx resources remaining in Hardware Service Manager removed paths will need manual cleanup.

REF: https://www.ibm.com/support/pages/reducing-or-removing-paths-multipath-lun