If you locate the disk ID's in IODFAULT.PUB.SYS, you will see that
Wide/Differential SCSI disks all have the same parameters. As long as you do
not configure a Single-Ended SCSI disk where you really have a
Wide/Differential SCSI disk, or vice versa, you can use any ID in that
group. What you see is normally a result of the product number being used as
the device ID (where valid in IODFAULT), while the device really has a
different internal ID.
Note: Watch out for ambiguous disk id's like ST34573WC, it can be a
Single-Ended or Wide/Differential device!

What I find more worrying about IOMAP is the frequency with which it reports
a configured disk not present, while you know it is definitely there and can
confirm it with :DSTAT ALL.

Fred Metcalf

-----Original Message-----
From: Gary Jackson
... in the IOMAP section I frequently see something like:
Device Adapter (10/4/24.6) --- PSEUDO
   Device (10/4/24.6) --- [ldev 1 HPC2490WD DISK]
   ***DEV CONFIG MISMATCH, ACTUAL ID = ST15150W***