> >
>  > Greetings,
>  >
>  >  I have a RAID fileserver plugged into a UPS and nut is able to
>  >  communicate with it successfully.  With the winds making the lights
>  >  flicker, I started looking into having the computer shut down when
>  >  power goes out for more than say 5 minutes or so.  Looking at the
>  >  documentation, I found that the 'true' solution is more like the
>  >  system goes into a safe state when the battery gets low, then the ups
>  >  eventually dies.  When power is restored, the UPS and computer are
>  >  supposed to both come back to life.  This would be a great system to
>  >  have in place, but it does sound a bit risky and so may not be worth
>  >  doing just to save my home fileserver.
>  >
>  >  The instructions and the conf file have the shutdown command of
>  >  'shutdown -h +0' which will halt the system.  The man page for halt
>  >  says the the disk cache will be flushed, but doesn't mention anything
>  >  about going to read-only or anything.  I suppose my first question is
>  >  whether or not flushing the cache is sufficient to save the RAID (5)
>  >  array, or if I need to find a way to get the file systems into read
>  >  only mode?
>  >
>  >  The second question has to do with a rc.d script that nut recommends
>  >  creating.  The script does a 'upsdrvctl shutdown' and then a sleep
>  >  120, basically waiting for the machine to die while in the script.
>  >  Won't this block the other rc.d scripts?  Also, is this the magic part
>  >  that enables the machine to auto power up when power is restored?
>  >
>  >  Changing the shutdown command in nut to 'shutdown -p +0' looks like
>  >  the sure fire way to get the system down clean before the power is
>  >  lost, but if my concerns are not valid, then I could be missing out on
>  >  some nice functionality for no reason.
>  >
>  >  Does anyone have experience with this?
>  >  I have my servers all using nut to safely shutdown.  My configuration is
>  > the servers are set up with one as master for nut, that master connected
> to
>  > the UPS.  The other servers are slaves and get their nut information from
>  > the master.
>  >
>  >  My setup has the servers wait until the UPS is on low battery, then they
>  > all shutdown.
>  >
>  >  As a separate part of the setup, the servers are set in their BIOS to
> power
>  > on, after a power failure.  This is in the BIOS power setup.
>  >
>  >  So if there is a minor power problem, the servers run from battery.  In
> a
>  > larger power outage, they are shutdown cleanly once the battery level is
>  > low, and power up automatically once power is restored.
>  >
>  >  In my upsmon.conf file I have this:
>  >  SHUTDOWNCMD "/sbin/shutdown -h +0"
>  >
>  >  If you want more specifics, I can look through the configuration files
> and
>  > email you relevant settings.
>  >
>
>  After doing more reading, I am confident that a shutdown -h would be
>  sufficient, but am a bit concern on the order of operations.  The nut
>  documentation has a recommendation to add a kill script as such:
>
>
>  #!/bin/sh
>
>  if [ "$1" == "stop" ]
>  then
>
>          if [ -f /etc/killpower ]
>          then
>                  echo "Killing the power, bye!"
>                 /usr/local/libexec/nut/upsdrvctl shutdown
>
>                  sleep 120
>          fi
>  fi
>
>  </copy>
>
>  Even if I name this zz_killpower.sh to make it run last, depending on
>  how long it takes FreeBSD to flush the cash after all rc.d scripts are
>  run, I could end up doing a dirty power down, right?  Without this, if
>  the power does come back while before the battery finally dies, the
>  system won't restart since the power was never fully interrupted at
>  the computer side?
>  You are reading the old documentation.  The current nut, 2.2, has complete
> rc scripts that are installed in /usr/local/etc/rc.d
>
>  You need only define the flag file you want to use in upsmon.conf
>
>  Also define what actions you want in that file as well.  You need to use
> the sample files installed in /usr/local/etc/nut and be sure to read the
> comments.
>

I have 2.2 installed and am using the existing scripts.  In the
comments in uspmon.conf, there is this part:

# --------------------------------------------------------------------------
# POWERDOWNFLAG - Flag file for forcing UPS shutdown on the master system
#
# upsmon will create a file with this name in master mode when it's time
# to shut down the load.  You should check for this file's existence in
# your shutdown scripts and run 'upsdrvctl shutdown' if it exists.
#
# See the shutdown.txt file in the docs subdirectory for more information.

POWERDOWNFLAG /etc/killpower

Which in the related documentation means I need the custom shutdown
script mentioned above which checks for the existence of the
/etc/killpower file before doing the upsdrvctl shutdown command to
kill the UPS before the battery is completely dead.  I suppose in your
situation you won't need this extra script as you run until the UPS is
critical whereas I am trying to kill the system a bit early, before it
is critical.

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.
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