[ILUG] UPS for home use?

[Conor Daly]

-----Original Message-----
From: Kenn Humborg <kenn at bluetree.ie>
To: Conor Daly <conor.daly at met.ie>
Cc: ilug <ilug at linux.ie>
Date: 29 June 2000 17:35
Subject: RE: [ILUG] UPS for home use?


>> Hell, if it comes to it, I'll let it spend 5 minutes fscking the disk on
>> restart (now if I could just think of a way to fake the uptime to pretend
>> the power loss never happened...)
>
>IIRC, someone wrote a kernel module that creates a /proc
>entry called /proc/uptime, so that you could do
>
># cat big-number-of-seconds > /proc/uptime
>
>to fake your uptime.
>
>Later,
>Kenn
>

But that would be cheating wouldn't it.  Could script something to store the
uptime and delete the record on a proper reboot but if the power goes, cat
it back to /proc/uptime.

Something like this in /etc/rc.d/init.d with stop symlinks in rc0.d and
rc6.d and start symlinks in rc1.d, rc2.d, rc3.d, rc5.d

#!/bin/bash

case in $1
start)
    cat /root/stored_uptime > /proc/uptime
;;
stop)
    rm -f /root/stored_uptime
;;
*)
    echo useage: $0 {start|stop}
;;
esac


Then set up a cron job to do

* * * * * cat /proc/uptime > /root/stored_uptime

If the system dies from a power cut, the stored_uptime file remains and is
used to update /proc/uptime while if a proper reboot is done, it gets
deleted.  Have to add the check for the existence of stored_uptime before
trying to cat it to /proc/uptime though.

All that remains then is to figure out how to differentiate between a power
cut and a system hang (not that it will hang eh?)

---
Conor Daly

Ph   +353 1 8326146

conor.daly at oceanfree.net
------------------------------------------