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Computer seance

Started: 2020-11-03 18:08:03

Submitted: 2020-11-03 20:59:23

Visibility: World-readable

In which the intrepid narrator enjoys a second Public Safety Power Shutoff

Two weeks after my first Public Safety Power Shutoff PG&E cut off my power again.

When the power went off I set up tea candles around the dining room table, where I sat with my laptop on battery power, the candles providing just enough ambient illumination to type in the near-dark. The net effect looked like a computer seance, as if I were trying to contact some reality beyond the vale of mortal knowledge. (From the perspective of running my computer and network on battery power, the Internet was a reality beyond the vale.)

Computer seance with Nagata
Computer seance with Nagata

For this outage I tweaked the settings on my UPS so it fir our needs better. I turned off the alarm so it wouldn't beep incessantly when the power went off, and wouldn't also alarm loudly when the battery was critically low. This was important because, due to a quirk of layout in our house, the network is powered in Calvin's room so the alarms would otherwise disturb him (and, possibly, awake him from sleep to deal with an entirely-unnecessary condition). (This I accomplished using the upscmd command, part of the Network UPS Tools suite. The NUT suite doesn't appear to have been actively developed for most of a decade, but I had very little trouble getting it up and running with my UPS.)

The other thing I did was set up upsmon to actively monitor the UPS and notify me when things changed. I wanted to set up pager notification for power events in lieu of audible alerts, for the previously-mentioned disadvantages of the audible alerts. (It briefly occurred to me to wonder my pager alias at Google was still working, and I think it probably is (because the pager file is a disaster and never gets cleaned up) but the first entry is my corp mobile number, which is not especially useful at the moment.) But the problem I discovered was that I had never set up outgoing email on my home server, because I had not intended to use my home server for email. This meant the simple way of sending myself a page — sending a text message to my phone through Verizon's email-to-text gateway — didn't work; and I didn't go far enough down the path of figuring out whether I wanted to set up email on my home server (ugh) or find a pager service with a suitable free tier (plausible) or come up with something else to send me text messages.

The first night the power was out I let the UPS battery run down to critical; and when it was critically low, about two hours after the power went out, upsmon noticed and sent me an alert (which didn't go anywhere) and shut my server down. This fulfilled my minimum-safety goals for shutting down the server safely (though, to be honest, modern journaled filesystems are rather good at maintaining integrity through unexpected shutdowns).

Between the neighbor's generator (during the day) and the UPS (at night) I got reasonable power coverage while the grid power was down; though I'd still prefer to not have to worry about the power going out simply because my local power utility wants to dispense with the potential liability of starting a cataclysmic wildfire.

Meddle not in the affairs of sysadmins, for they are
quick to violence, and have no need for subtlety.