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<font size=3>At 11:01 PM 3/8/2012, Charles Lepple wrote:<br><br>
[Snip]<br><br>
<blockquote type=cite class=cite cite="">> EPO on the other hand is a
key requirement of my next feature: The<br>
> ability of a UPS driver to declare that the UPS is dying of
some<br>
> critical condition and that it must be shut down in such a way
that<br>
> manual human intervention is required to restart it. EPO is
also<br>
> intended to be triggered automatically, whereas FSD (I think) is
always<br>
> intended to be manually introduced by a human systems manager.<br>
> <br>
> I.e. in an ideal configuration everything should restart and reboot
and<br>
> return to operational status after "upsmon -c fsd" once
mains power<br>
> returns or if power was never actually off; whereas with
"upsmon -c epo"<br>
> then everything should power down and stay off even if mains
power<br>
> remains on and steady.<br><br>
This is an interesting distinction (one that a few drivers make in their
different shutdown commands, but that is not currently tied to
FSD).<br><br>
The reason why I advocated usurping the "FSD" status was
because it is the only other status besides "OB LB" that is
currently guaranteed to trigger a shutdown. I wonder if we could just use
FSD with some other status option to indicate whether the driver should
request a restart when the power returns.<br><br>
I've CC'd Bill Elliot to get his thoughts on the use cases that led to
suggesting the external shutdown trigger - it might dovetail with
this.<br><br>
> For example I would have used "FSD" to shut down in power
blackouts<br>
> where I knew the power could not return before the batteries ran
low,<br>
> and thus I would have conserved battery charge for the inevitable
short<br>
> hiccups that occur after a long blackout, but still been able to
enjoy<br>
> automatic restart after the blackout in case power returns while
I'm<br>
> sleeping, etc.<br>
> </blockquote><br>
Just my .02. The action the UPS takes when power is restored is
(should be?) independent of the use of "FSD". The driver
can configure the UPS to do what is required for the given environmental
information before issuing "FSD". This would be similar
to the difference between the "shutdown.return" and
"shutdown.stayoff" commands...but driven by driver
logic.<br><br>
The reason that I brought the use of "FSD" up initially was
that the UPS I was working with had multiple communication channels to it
and the channel that NUT was not using could initiate a UPS
shutdown. In that case the driver could see that a shutdown timer
was active and issue the "FSD" so the computers being powered
by the UPS could do a graceful shutdown.<br><br>
Bill<br>
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