[patook]

Hello, I have dual VIO servers using MPIO to a SAN. I created the devices on the vio server using the mkvdev command. What is strange though is the order of the disks on the lpar does not match the LUN number order. In other words, hdisk3 might be LUN 61 and hdisk4 might be 60 (this is the L60 number that shows up on lscfg -l hdisk4 on the LPAR). If I remove all the hdisks with rmdev -dl hdisk3 (same for hdisk4), they will recreate in the same order.


What controls the order of disk discovery with VIO disks?

[captain_blie]

AIX used to assign hdisk numbers based on the order in which the drives were discovered. Then the hdisk number was stored in the OD with the location code of the devices, this is why hdisks often differed from what is seen in SMS.

The best I have been able to figure with MPIO is that this process still holds true.

If you have patience and time you could go through and change your hdisk numbers but it is often not worth the effort. You can easily cross reference the HDISK numbers to serial number and then write a script or use excel to cross reference this to corresponding hdisk numbers for the two VIO servers. Having a developed process for doing this will aid in long term supportability of your servers.

[Koetje]

What you can do more easily ....

mkvdev on VIO the first LUN
cfgmgr on the LPAR -> hdiskx
mkvdev on vio the second LUN
cfgmgr on the LPAR -> hdiskx+1
etc. etc. etc.

its a bit more work but in the end you got the disks like you want to

Dont forget to delete the disks on the LPAR before you begin as it numbers new disks from the last it detected (lsdev |grep hd) to see you disks