From owner-freebsd-questions@FreeBSD.ORG Thu Jan 10 23:10:22 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id F035316A420 for ; Thu, 10 Jan 2008 23:10:22 +0000 (UTC) (envelope-from derek@computinginnovations.com) Received: from betty.computinginnovations.com (mail.computinginnovations.com [64.81.227.250]) by mx1.freebsd.org (Postfix) with ESMTP id 7A24913C468 for ; Thu, 10 Jan 2008 23:10:22 +0000 (UTC) (envelope-from derek@computinginnovations.com) Received: from p28.computinginnovations.com (dhcp-10-20-30-100.computinginnovations.com [10.20.30.100]) (authenticated bits=0) by betty.computinginnovations.com (8.13.8/8.13.8) with ESMTP id m0ANACek062021; Thu, 10 Jan 2008 17:10:13 -0600 (CST) (envelope-from derek@computinginnovations.com) Message-Id: <6.0.0.22.2.20080110170728.0244cad0@mail.computinginnovations.com> X-Sender: derek@mail.computinginnovations.com X-Mailer: QUALCOMM Windows Eudora Version 6.0.0.22 Date: Thu, 10 Jan 2008 17:09:54 -0600 To: "Derrick Ryalls" From: Derek Ragona In-Reply-To: References: <6.0.0.22.2.20080110025841.023a9bb8@mail.computinginnovations.com> <6.0.0.22.2.20080110155430.023d29d8@mail.computinginnovations.com> Mime-Version: 1.0 X-ComputingInnovations-MailScanner-Information: Please contact the ISP for more information X-ComputingInnovations-MailScanner: Found to be clean X-ComputingInnovations-MailScanner-From: derek@computinginnovations.com X-Spam-Status: No Content-Type: text/plain; charset="us-ascii"; format=flowed X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: FreeBSD Questions Subject: Re: Nut and RAID on FreeBSD 7.0 X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 10 Jan 2008 23:10:23 -0000 At 04:43 PM 1/10/2008, Derrick Ryalls wrote: > > > > > > 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 > > > > > > > > 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. Also, the first thing that starts to go bad on a UPS is the batterylife. So just shutting down on low battery works well. In my case, I don't worry about the UPS, it is so low on power by then it just chirps for another minute or so then it dies, completely exhausted. -Derek -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. 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