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Full Discussion: Wrong Array...
The Lounge War Stories Wrong Array... Post 303026919 by bakunin on Wednesday 5th of December 2018 06:57:18 AM
Old 12-05-2018
Here is my personal "power-loss-story" and it has nothing to do with a power-button:

Back around 2000 i was working for a data center, which - nothing really unusual - had a large ~1000hp diesel generator to back up its UPS. This diesel was tested every year once by switching it on for 2 minutes. Everything worked fine.

Now, what happens if you run such a system for two minutes a year? Disaster struck and showed to the responsible people exactly what happens in such a case: during a heavy thunderstorm the nearby transformer station (or, specifically, its large 6m-diameter capacitor was hit by a lightning. The whole area was suddenly without electrical current and the remains of the capacitor lay across half of the street in pieces not bigger than a few centimeters each.

First, our UPS kicked in - as planned. Then, when the UPS batteries went low, the diesel started. It ran for about 5-6 minutes, then stuck with a piston seizure because running keeps such a machine lubed. When it doesn't run all the bearings eventually run dry of oil. So far, so bad and our data center stood without electrical power.

What makes the story interesting, though, is: at the same time adear friend of mine (shockneck) worked for another data center across the street. So, two days after the incident, we sat in a cafe commiserating about life as an admin. And he told me, they had a UPS, backed by a diesel. And because they knew that engines have to run every now and then to remain properly lubed they switched it on every month and let it run for 10 minutes. Alas, their diesel gave up a few minutes after starting. You know, when letting it run so often you need to refill the tank now and then.....

bakunin
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UPSDRVCTL(8)						      Network UPS Tools (NUT)						      UPSDRVCTL(8)

NAME
upsdrvctl - UPS driver controller SYNOPSIS
upsdrvctl -h upsdrvctl [-t] [-v] (start | stop | shutdown | status) [ups] DESCRIPTION
upsdrvctl provides a uniform interface for controlling your UPS drivers. You should use upsdrvctl instead of direct calls to the drivers whenever possible. When used properly, upsdrvctl lets you maintain identical startup scripts across multiple systems with different UPS configurations. OPTIONS
-h Display the help message. -t Enable testing mode. This also enables verbose mode. Testing mode makes upsdrvctl display the actions it would execute without actually doing them. Use this to test out your configuration without actually doing anything to your UPS drivers. This may be helpful when defining the 'sdorder' directive in your ups.conf(5). -v Enable verbose messages. COMMANDS
upsdrvctl supports four commands - start, stop, shutdown and status. They take an optional argument which is a UPS name from ups.conf(5). Without that argument, they operate on every UPS that is currently configured. start Start the UPS driver(s). stop Stop the UPS driver(s). shutdown Command the UPS driver(s) to run their shutdown sequence. Drivers are stopped according to their sdorder value - see ups.conf(5). WARNING: this will probably power off your computers, so don't play around with this option. Only use it when your systems are pre- pared to lose power. status Check the status of the UPS driver(s). If every UPS that has been checked is running, then the exitcode will be 0. If one seems to be missing, the exitcode will be 1. BUGS
The status checking is rudimentary, and really only looks for the presence of .pid files. If you really want to know if your UPS drivers are alive and well, upsmon(8)'s NOCOMM notifier does a fine job. SEE ALSO
nutupsdrv(8), upsd(8) ups.conf(5) Internet resources: The NUT (Network UPS Tools) home page: http://www.exploits.org/nut/ NUT mailing list archives and information: http://lists.exploits.org/ Wed Oct 16 2002 UPSDRVCTL(8)

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