topic Re: ES40 CPU Disable in Operating System - OpenVMS

ES40 CPU Disable

Jack Trachtman — Fri, 18 Jan 2008 16:22:29 GMT

I would like to disable a cpu module on an ES40 (I have restored a copy of VMS from another host that has fewer CPUs and am seeing licensing complaints on boot).

I don't see anything in the ES40 User Guide,
but I see this set of console variables:

...
lp_count 0
lp_cpu_mask0 f
lp_cpu_mask1 f
lp_io_mask0 ff
lp_io_mask1 ff
lp_mem_size0 0
lp_mem_size1 0
lp_shared_mem_size 0
...

Does lp_cpu_mask0 (or mask1) control active CPUS? What's the difference between mask0 & mask1? What does the prefix lp stand for?

Tia

Re: ES40 CPU Disable

EdgarZamora — Fri, 18 Jan 2008 17:13:49 GMT

Those lp variables are for Galaxy. They aren't relevant to what you want to do. I've never done this myself, but check out the console variable cpu_enabled instead.

Re: ES40 CPU Disable

EdgarZamora — Fri, 18 Jan 2008 17:29:51 GMT

Here's more info in case you don't have documentation:

5.14.10 cpu_enabled
The cpu_enabled environment variable sets a bit mask that enables or
disables specific CPUs on a multiprocessor system.
Disabling a CPU may be necessary if a number of errors are reported on a specific
CPU. These errors might be displayed during power-up or might be displayed
with the show fru or show config command.
Disabled CPUs are prevented from running the console or the operating system.
Bit 0 of the mask corresponds to CPU 0, bit 1 to CPU 1, and so on. A zero in the
bit mask prevents the corresponding CPU from running; a one allows it to run.
The bit mask is expressed as a hexadecimal value.
The value of cpu_enabled takes effect only after you reset the system by pressing
the Reset button or by issuing the init command.
The cpu_enabled environment variable is typically used in benchmark testing.

Re: ES40 CPU Disable

Jack Trachtman — Fri, 18 Jan 2008 18:28:56 GMT

Thanks Edgar - somehow I'd missed the obvious env variable