How to prevent underclocking when running with 1 redundant power supply

[Cy Schubert]

On October 27, 2019 2:07:12 PM PDT, Craig Leres <leres at freebsd.org> wrote:
>I have a nameserver running 11.3-RELEASE-p4. It has a Supermicro
>X9SRi-F 
>motherboard in a 1U chassis with redundant PWS-406P-1R power supplies 
>(400W each).
>
>Site power is out thanks to a PG&E "public safety power shutdown" and I
>
>find that the system is really unhappy. It looks like it is 
>underclocking due to one power supply not being powered:
>
>     # sysctl dev.cpu.0.freq_levels dev.cpu.0.freq
>    dev.cpu.0.freq_levels: 3001/80000 3000/80000 2900/75926 2700/69558 
>2600/65698 2500/62669 2400/59709 2200/53206 2100/50412 2000/46962 
>1800/41676 1700/38423 1600/35918 1500/33467 1300/28074 1200/25787
>     dev.cpu.0.freq: 1200
>
>I found powerd and tried this:
>
>     powerd_enable="YES"
>     powerd_flags="-a max -b max -n max"
>
>which works... once it's started. Now I'm finding one system has a 
>difficult time booting because powerd is started so late in the boot 
>process.
>
>Is there a sysctl I can put in loader.conf to disable this
>underclocking 
>behavior?
>
>Thanks!
>
>		Craig
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dev.cpu.0.freq can be set by hand (or script).

I suppose your BIOS automatically reduces the clock rate with one power supply connected. I assume that's a safety feature one might want to investigate before incurring possible undesired consequences. 


-- 
Pardon the typos and autocorrect, small keyboard in use. 
Cy Schubert <Cy.Schubert at cschubert.com>
FreeBSD UNIX: <cy at FreeBSD.org> Web: https://www.FreeBSD.org

The need of the many outweighs the greed of the few.

Sent from my Android device with K-9 Mail. Please excuse my brevity.