[CentOS] Power-outage

Fri Jul 1 13:13:55 UTC 2011
John Hodrien <J.H.Hodrien at leeds.ac.uk>

On Fri, 1 Jul 2011, Robert Heller wrote:

> With a non-Linux compatable UPS, you can use a old analog serial modem
> as a power sensor. If the machine has a serial port (RS-232), you can
> plug the modem into the wall outlet and connect it to the computer's
> serial port.  When the power goes out, the modem goes off and powerd can
> sense the loss of Modem Ready and treat that as a 'power failure'
> signal.  This trick works for cheap, obscure or basic *dumb* UPSs.

Nice. ;)

Another trick I used was to hook the monitor up to non-UPS power, and connect
the USB hub within it to the PC.  A udev trigger than runs a script when the
device appears or disappers.  In my case it was to reconfigure the displays
when monitors were turned on, but I'd not thought of using it for UPS
monitoring.

jh