[CentOS] A problem with power outages

Mon Mar 26 01:15:18 UTC 2012
William Warren <hescominsoon at emmanuelcomputerconsulting.com>

On 3/25/2012 2:39 PM, Timothy Murphy wrote:
> Ryan Wagoner wrote:
>
>> Additionally if your computer BIOS supports configuring the AC recovery
>> power mode to always on, the computer will start back up. Most default to
>> last state, which doesn't work as well since shutting down will power off
>> the computer, which means that last state is off. There are some
>> workarounds to change the shutdown sequence to just halt and not power
> Thanks again for your response.
> I did an experiment which I probably should have done before,
> to find out exactly what happens if the power is cut off, and then restored.
> You were completely correct.
>
> My server is an HP MicroServer (running CentOS-6.2).
> If the machine was running before being cut off
> then it reboots normally when power is restored.
> If however it is shutdown before the power is cut
> then it does not reboot when power is restored.
> As you say, it always returns to the state it was in when the outage occurs.
>
> I looked in the BIOS, but there is no option on this machine
> to change that.
>
> So I shall know what to do when I get a UPS.
> If there is no better setting I can just allow the UPS to become exhausted
> if the outage lasts longer than the life of the UPS.
>
>
in the apc software(or nut worst case) you'll be able to specify that 
after x minutes it will shutdown.  Better to have a clean shutdown and 
have to hit the power button than a dirty one and risk corrupting your 
filesystem.