Simpler Navigation for Servers and Operating Systems - Please Update Your Bookmarks
Completed: a much simpler Servers and Operating Systems section of the Community. We combined many of the older boards, so you won't have to click through so many levels to get at the information you need. Check the consolidated boards here as many sub-forums are now single boards.
If you have bookmarked forums or discussion boards in Servers and Operating Systems, we suggest you check and update them as needed.
Operating System - Tru64 Unix
cancel
Showing results for 
Search instead for 
Did you mean: 

Offlining a CPU

SOLVED
Go to solution
Steve Wilde_1
Occasional Visitor

Offlining a CPU

Hello All - I have a GS140 (8400) with four CPU's, 0, 1, 2, 3. I would like to off-line CPU 3 to prevent it from being used. The system is at the console prompt. When I tried to set the cpu_enabled setting to fff7 I could no longer access my hard drives. Can somebody help me? Thanks.
5 REPLIES
Michael Schulte zur Sur
Honored Contributor
Solution

Re: Offlining a CPU

Hi,

my idea would be set cpu_enabled 7

Michael

the origin for that is the following note in the readmes for v6.6 firmware

For example changing cpu_enabled, on a four-CPU system, from F to 0 will disable cpu1-3
Hein van den Heuvel
Honored Contributor

Re: Offlining a CPU

WHY do you want to offline a CPU? Aplication (license) pricing?

I would try to avoid changing the mask because it needs a reboot to undo. If you can get away with it, just use 'offline 3' or 'psradm -f 3'. Of course if that might not make the legal requirements...

I would also opt for mask '07'. btw... are the CPU tightly packed from the right front?

I don't understant how disabling a (non-primary) cpu would prevent access to the hard drives ?! What does show dev/ show config tell you at the P00>>> prompt ?
You did not accidently reboot from a different boot disk/file by accident? (show boot_def_dev or show boot*)

Also... which version/patchlevel of Tru64 ?

fwiw,
Hein.



Mohamed K Ahmed
Trusted Contributor

Re: Offlining a CPU

From the SRM console you can disable CPU 3 by setting the cpu_enabled to 7. Probably it is set to ff or f now

P000> show cpu_enabled
P000> set cpu_enabled 7
P000> boot

Mohamed
Steve Wilde_1
Occasional Visitor

Re: Offlining a CPU

Well, I wanted to offline it because I'm getting KMF's on CPU3 & I don't have support on the thing. I only need two CPU's for my application.

I know that setting the CPU mask shouldn't affect seeing disks but when I leave the mask at ffff (where it was by default) I can boot to my disks and when I change it to fff7 I can see the drives with the sho dev but when I try to boot to any of them I get a message saying the drives are no longer valid. Maybe this is a seperate issue though.

I don't have a valid O/S on it right now (it corrupted during an LSM mirror function when CPU3 KMF'd. I can boot the image but the root domain is corrupted.) I do have firmware 6.3 on though.

Thanks for the help. -Steve
Mohamed K Ahmed
Trusted Contributor

Re: Offlining a CPU

the cpu_enabled is a hex number
CPU # ( 1=enabled, 0=disabled)

1 2 3 4 CPU_ENABLED
1 0 0 0 = 1
1 1 0 0 = 3
1 1 1 0 = 7
1 1 1 1 = f or ff or ffff it doesn't matter

So to disable CPU 3 and enable CPU 0 , 1 and 2, you have to set the cpu_enabled to 7

Mohamed