From owner-freebsd-questions@FreeBSD.ORG Wed Aug 11 23:01:54 2010 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 0B3BA106564A for ; Wed, 11 Aug 2010 23:01:54 +0000 (UTC) (envelope-from gull@gull.us) Received: from mail2.sea5.speakeasy.net (mail2.sea5.speakeasy.net [69.17.117.41]) by mx1.freebsd.org (Postfix) with ESMTP id D2CF78FC1B for ; Wed, 11 Aug 2010 23:01:53 +0000 (UTC) Received: (qmail 29329 invoked from network); 11 Aug 2010 23:01:52 -0000 Received: from dsl081-163-112.sea1.dsl.speakeasy.net (HELO ringbill.gull.us) ([64.81.163.112]) (envelope-sender ) by mail2.sea5.speakeasy.net (qmail-ldap-1.03) with AES256-SHA encrypted SMTP for ; 11 Aug 2010 23:01:52 -0000 Received: from localhost ([127.0.0.1] helo=www.gull.us) by ringbill.gull.us with esmtp (Exim 4.71 (FreeBSD)) (envelope-from ) id 1OjKIt-0005fS-FY; Wed, 11 Aug 2010 16:01:47 -0700 Received: from d-69-91-158-125.dhcp4.washington.edu ([69.91.158.125]) (SquirrelMail authenticated user gull) by www.gull.us with HTTP; Wed, 11 Aug 2010 16:01:47 -0700 Message-ID: In-Reply-To: <3AB9F23A-B56C-4176-83C9-F248161066B9@cwis.biz> References: <3135A83C-6FD9-4C3B-958F-11EE85221061@mac.com> <5304A319-0406-4510-B6B2-8FD609239FF9@cwis.biz> <43a2b1b16a03a5c58dfb7beaadd0c535.squirrel@www.gull.us> <3AB9F23A-B56C-4176-83C9-F248161066B9@cwis.biz> Date: Wed, 11 Aug 2010 16:01:47 -0700 From: "David Brodbeck" To: "Ryan Coleman" User-Agent: SquirrelMail/1.4.20 MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Priority: 3 (Normal) Importance: Normal Cc: freebsd-questions@freebsd.org Subject: Re: UPS question 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: Wed, 11 Aug 2010 23:01:54 -0000 On Wed, August 11, 2010 1:18 pm, Ryan Coleman wrote: > On Aug 11, 2010, at 3:06 PM, David Brodbeck wrote: > >> On Wed, August 11, 2010 12:25 pm, Ryan Coleman wrote: >>> He thinks that at 500W needed it would give me about 12 minutes on a >>> 1400VA. My consideration is, then, give the server 2 minutes on >>> battery. >>> If full power has not been returned, shut down the server but leave the >>> modem (w/ wireless) and switch running with power for up to 6 hours. >> >> A bit of advice: If this is an unattended system, give some thought to >> how >> you will boot the server back up if the outage is longer than two >> minutes >> but shorter than six hours. Most UPS installations have *some* kind of >> race condition issue if power comes back after the servers have begun a >> shutdown, but in your case it's an unusually long window. > > Meaning that my 2-minute window is unusually long? If the UPS can support > the system for 12 minutes, I say give it 20% of the life of the support > because our power outages here are usually spikes that kill my current web > server (but amazingly *not* my file server). In fact, one of those power > fluxes occurred last night. I love storms for the light shows, but hate > them for the toll they take on my servers. Nope, 2 minutes is fine, maybe even short depending on how long your system takes to shut down. What I'm asking about is this scenario: 1. Power goes out. 2. Server shuts itself down after 2 minutes. 3. Power comes back on before the UPS batteries are exhausted. The server never sees a power cycle, so it doesn't boot itself back up until someone physically goes and pushes the button.