Solaris 7 x86 - stop cpu 0

Hi.

I have a dual-PII server with Solaris 7 on it. I need to perform maintenance task by stopping each CPU for a while (to cool down), while the other works.
I have no problem stopping cpu 1 with
  psradm -f 1
command, but, when i try to stop cpu 0 by a similar command, i get:
  psradm: processor 0: Device busy

I guess that this processor is locked by kernel, or something like that.
So, here is the question:
IS IT POSSIBLE to stop cpu 0 and run the system on cpu 1 only?

If someone tells me that it is possible, i will raise points to 200 for the answer HOW can i do it...

Regards,
Tal


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seredaAsked:
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jlevieConnect With a Mentor Commented:
I don't think so. I suspect that this is an intel platform problem relating to the way multiple cpu's are implemented. I vaguely recall that you can't even boot an intel multi-processor without having the first processor installed.

I guess I don't understand why you should need to "cool down" one of the processors. It would seem to me that would imply that you've got a problem with insuffucient air flow through the box and additional fans would be the logical solution.
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seredaAuthor Commented:
Thanks for comment, jlevie,
waiting for other opinions...

As for cooling down - yep, additional fans will do the work, but stopping cpus has some advantages: first, it's a little bit more flexible and reliable (imho) and second, and most important, you don't have to go to the server's location and stop it.
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festiveCommented:
As far as I am aware no! you must have a cpu dedicated to the OS, I believe that this is the first one it finds.

you should look at the cryotech cooling system... very nice.

I am sorry to say (are there any electrical engineers out there) I believe that your attentions to doing this may be misguided, ie I do not believe that deselecting a CPU will allow it to cool, as the circuitry to the unit cannot be removed and the overclocking (assuming that there is some) will be BUS-WIDE regardless of the usage of the CPU.

Solaris uses a process called symmetric multi-processing (for example) which enables it to spread low-level cpu instructions accross CPU's.

Please forgive me if I have misread your intentions, But I would (given the above) be unsure as to why you would want to convert a multi-cpu machine back into a single-cpu system anyway.
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seredaAuthor Commented:
Well, the reasons i thought of is that CPU is heating not just because it's power-on and bus activity takes place, but because it constantly runs commands.

As a proof, i can think of different OSes (say, DOS and OS/2) - the latter is sending HLT instruction (or something) to the processor while it's not needed (idle cycle), and actually CPU stays pretty cool under slight load.

So, i guessed that stopping it may help to cool it down.

Seems like it's not really possible to turn off CPU 0... Well, let's wait a little bit longer...

Approach to the problem is that server is physically unaccessible.
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seredaAuthor Commented:
Comment accepted as answer
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seredaAuthor Commented:
Well, it seems that there's no way to stop CPU 0 on intel platform. :(
Thanks for participating though :)
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