Nut and RAID on FreeBSD 7.0

[Bob Johnson]

On 1/10/08, Derrick Ryalls <ryallsd at gmail.com> wrote:

>
> Perhaps I need to re-evaluate my line of thinking.  Light sometime
> flicker, but power almost never goes out.  When it does it is either
> back on in less than 1 minute, or out for hours.  If the UPS detects
> critical correctly and gives me at least a minute before death, then
> that should be plenty of time for the system to auto-shutdown.  Guess
> I will have to do some experimentation tonight.

While you experiment, keep in mind the following sequence of events:

-- Power fails
-- UPS signals low battery
-- System shuts down
-- Power returns before UPS shuts itself down
--> System never reboots, because it never lost power.

Getting around this is the tricky part. I haven't used NUT in about
seven years, but back then the recommendation was to shut down to
single user mode and run a script that delayed for some time longer
than the remaining battery life of the UPS, then rebooted the system.
There didn't seem to be an easy hook for running a script after
shutting down to single user mode (maybe there is now).

I haven't looked at NUT recently, but I expect the various flags that
you are supposed to test are another way around this problem.

- Bob