[Nut-upsuser] Detect ups.status on battery seems a little delay

Kris Jordan nut.kj at sagebrushnetworks.com
Wed Feb 20 17:02:31 UTC 2013

Oleg Semyonov wrote, On 2/20/2013 12:39 AM:
>> UPS model: APC Smart-UPS 750 (051D/0002)
>> But when UPS is offline, status will not change to OB immediately.
>> After test many times. this delay time didn't have any rules. Maybe
> immediately or few seconds or few minutes.
>> It will cause doing ONBATT action also delayed.
> I asked exactly the same question on the 29th of January, and got nothing in
> reply.
> It doesn't seem to be a bike shedding problem, so nobody bothered, including
> developers
> (about using non-documented and probably non-supported option value).
> http://en.wikipedia.org/wiki/Parkinson's_law_of_triviality
> Short solution: set pollinterval=0 in driver configuration. It will report
> OB/OL immediately
> (but with a bit more CPU load).
> Full description: see my question here:
> http://lists.alioth.debian.org/pipermail/nut-upsuser/2013-January/008195.html

Does the problem persist outside of a VM?

    Set polling frequency, in seconds, to reduce the USB data flow.
    Between two polling requests, the driver will wait for interrupts
    (aka UPS notifications), which are data changes returned by the UPS
    by itself. This mechanism allow to avoid or reduce staleness
    message, due to the UPS being temporarily overloaded with too much
    polling requests. The default value is 30 (in seconds).

Sounds like NUT supports interrupts with this driver.

Pollfreq vs. pollinterval, I also wonder what is up with those two options.

Is that a Microlink Smart-UPS? Perhaps one of its compatibility mode 
limitations are no interrupts.

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