changing hdisk order

[drun97]

What are the steps in changing the hdisk order of internal disks without pulling the disks out and then running cfgmgr on each disk. I'm wanting to manually assign hdisk numbers to specific disks.

 

[mrn]

Why?

Mike

Unix *is* user friendly. It's just selective about who its friends are.

 

[p5wizard]

Only thing I can think of, is remove all disks, then run cfgmgr selectively:

lsdev -Ccdisk -F name|xargs -n1 rmdev -dl
cfgmgr -l scsi0
...
cfgmgr -l scsiX
cfgmgr -l fscsi0
...
cfgmgr -l fscsiY
consecutively for all scsi/FCscsi adapters

But you can't remove the disks which are already in rootvg. You'll get error message during the rmdev stage.

Why you'd want to do that, I'd like to know also. Besides, if you later add more SAN LUNs for instance, your numbering might be all messed up again anyway...


HTH,

p5wizard

 

[Yrrk]

If i recall correctly cfgmgr assigns hdisk #'s in order by the drive's serial numbers. With SSA drives we used to put them into their enclosure in serial number order such that AIX would assign them hdisk1 through whatever in nice neat order.

 

[DukeSSD]

If I remember correctly cfgmgr assigns hdisk numbers by bus and then device.
All scsi first, onboard scsi then adapter scsi, then SSA.
SSA adapter, then SSA enclosure then enclosure slot number.
I seem to remember the pdisks were related to the slot order and don't ever remember putting them in by serial number.

But WHY would you care?

If you muck them all about, then take a mksysb, then try to restore the mksysb all sorts of problems are likely to happen....because the mksysb will surely take the disks as it finds them, or rather as cfgmgr would find them on a clean install.