Dummy hdisk disapear on reboot

[MoreFeo]

Hi,
We're migrating our SAN storage from DS4800 to HP EVA8400.
I want to create some dummy hdisks in our LPARs, so the new hdisks will have consecutive numbers and it will be easier to manage.
I've created several dummy hdisks with this command:

mkdev -l hdiskX -p dummy -c disk -t hdisk -w 0000

I've noticed that it complains about not having the dummy device, so it defines SSA disks.

We've completely rebooted our server (VIO reboot), so we've rebooted all our LPARs, and now the dummy hdisks have disapeared.

Is there a way to define dummy hdisk in a way they won't disapear?

Thanks

 

[mrn]

The disks will come in, in the order you mapped them on your VIO(s)

You shouldn't need to pad.

I have noticed however on 6.1 that this isn't always the case, but a couple of rmdev's and cfgmgr eventually bring them in correctly.....

Mike

"Whenever I dwell for any length of time on my own shortcomings, they gradually begin to seem mild, harmless, rather engaging little things, not at all like the staring defects in other people's characters."

 

[MoreFeo]

The issue is that they've mapped and unmaped a lot of disks, so the hdisks list has some gaps like:

# lspv
hdisk3        0009461e21a7022c            rootvg   active
hdisk4        0009461e21a70278            UT1VG    active
hdisk5        0009461e21a702b8            UT1VG    active
hdisk8        0009461e21a702fb            UT1VG    active
hdisk10       0009461e21a7033b            UT1VG    active
hdisk13       0009461e21a7037e            UT1VG    active
...

As you see there some gaps like hdisk0, hdisk1, hdisk2, hdisk6, etc... I've checked with lsdev -Cc disk and they aren't defined, so new hdisks will take these names.

In other LPARs it's the same, but with different hdisks names.

I'm trying to define some dummy hdisks to fill these gaps, so the new hdisks will start all with the same name.
This will make it easier to manage, and also there will be some HACMP clusters so we want to have the same hdisks names in both nodes.

So I defined some dummy hdisks with the command in my first post, but after a shutdown the hdisks had disapeared.

What is the correct way to define dummy hdisks?

Thanks

 

[mrn]

If it were me I'd remove all the current disks and remap them, rather than going down the dummy disk route.

But if thats the way you want to go; create a script with all your mkdev cmds in and create a /etc/rc.disk to set them up on boot.

Mike

"Whenever I dwell for any length of time on my own shortcomings, they gradually begin to seem mild, harmless, rather engaging little things, not at all like the staring defects in other people's characters."

 

[MoreFeo]

Thanks, I'll try with the scripts.