[sf-lug] PG&E had a power outage for ... spanning about ...

Michael Paoli Michael.Paoli at cal.berkeley.edu
Tue Apr 19 01:32:45 PDT 2016

Ah, correcting the when, etc.:
PG&E had a power outage for approximately 1 hour 19 minutes and 22 seconds,
spanning about:

The first hardware I looked at regarding logging of outage didn't immediately
log power outage/restoration, but only logged it after it had been  
persistent a while,
hence the offset.  The outage time above should be quite accurate -  
it's loss of
link to the Ethernet switch (not on UPS), as caught by NTP synced host  
The restoration time isn't quite as accurate, as that host had to complete
POST, etc., and any bootloader timeouts, before booting and starting to log,
and also it's not NTP synced as regularly nor was it NTP synced before it
booted and resumed logging (and hasn't been brought fully on-line to  
NTP sync yet) ...
looks like it's about a minute and 10 seconds fast on its clock so,
having subtracted that data point to what it logged ... and also, what  
the heck,
check timing delay from power up to first data logged ... right around  
a minute and 18
seconds, so, subtracting that out too, to come up with
end time of outage now shown as adjusted above.

Hmmm, interestingly, looks like the laptop battery just barely didn't  
quite make it
through the entire outage ... last (so far) I found that it logged  
before powering down,
was at:
(yeah, I wouldn't trust all those digits on the fractional second as  
accurate, but that's
what it logged) ... so ... that'd be about 1 minute and 8 seconds  
short of power restoration.
So ... made it through about 98.57% of the outage, ... but alas, would  
need 100% for the
host to have stayed up (and in any case, it still would be off-line  
due to lack of UPS on
the other equipment).

So ... looks like that first hardware logging I peeked at only logs  
when it's been persistent for about 30 minutes (not sure about its  
logging algorithm
if the power does additional flip-flops within 30 minute window).

> From: "Michael Paoli" <Michael.Paoli at cal.berkeley.edu>
> Subject: "all better" (up again): Re: (temporarily) down: SF-LUG  
> (but lists up) ... likewise some BALUG bits down ...
> Date: Mon, 18 Apr 2016 18:45:14 -0700

> DO NOT REPLY ALL (unless you're subscribed to BOTH lists)
> "all better" - these sites/resources are up and online again.
> PG&E had a power outage for approximately 1 hour and 20 minutes,
> spanning about:
> 2016-04-18T15:56+0000--2016-04-18T17:16+0000
> 2016-04-18T08:56-0700--2016-04-18T10:16-0700

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