From owner-freebsd-questions@FreeBSD.ORG Fri Jun 15 23:54:15 2012 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 84F5E106564A for ; Fri, 15 Jun 2012 23:54:15 +0000 (UTC) (envelope-from perrin@apotheon.com) Received: from oproxy1-pub.bluehost.com (oproxy1.bluehost.com [IPv6:2605:dc00:100:2::a1]) by mx1.freebsd.org (Postfix) with SMTP id 46C2E8FC08 for ; Fri, 15 Jun 2012 23:54:15 +0000 (UTC) Received: (qmail 14098 invoked by uid 0); 15 Jun 2012 23:54:15 -0000 Received: from unknown (HELO box543.bluehost.com) (74.220.219.143) by oproxy1.bluehost.com with SMTP; 15 Jun 2012 23:54:14 -0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=apotheon.com; s=default; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID:Subject:To:From:Date; bh=xXL5PIhcNZeGcTVZCmT6/6Ld4inJmL/Q6iUujfrjTkM=; b=VtOAXH5Mk9jDYXhoL/JCBQI6bJCVVs40u4liGduLPb4s06/fYxdazhEkFBVPXMNmCCv+u7KOEFDNJDF5biXSuxza3jnnEDAhg+B01QMpyPbvPPwCk9JtIb+3jBh1wjv5; Received: from [24.8.180.234] (port=60503 helo=localhost) by box543.bluehost.com with esmtpsa (TLSv1:AES128-SHA:128) (Exim 4.76) (envelope-from ) id 1SfgLG-0002NQ-Fj for freebsd-questions@freebsd.org; Fri, 15 Jun 2012 17:54:14 -0600 Date: Fri, 15 Jun 2012 17:54:14 -0600 From: Chad Perrin To: freebsd-questions@freebsd.org Message-ID: <20120615235414.GA15957@hemlock.hydra> Mail-Followup-To: freebsd-questions@freebsd.org References: <201206151249.q5FCnnKF019002@mail.r-bonomi.com> <20120615160005.GB20814@hemlock.hydra> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Identified-User: {2737:box543.bluehost.com:apotheon:apotheon.com} {sentby:smtp auth 24.8.180.234 authed with perrin@apotheon.com} Subject: Re: Uptime [OT] 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: Fri, 15 Jun 2012 23:54:15 -0000 On Fri, Jun 15, 2012 at 11:47:55PM +0000, David Brodbeck wrote: > On Fri, Jun 15, 2012 at 4:00 PM, Chad Perrin wrote: > > No power conditioning (implied by no UPS) is nothing to brag about. > > If your utility power is very -- common now in places with buried > utilities -- a UPS of the non-enterprise variety can actually make > reliability *worse*. I've found that standby-type UPSs (like the > popular APC BackUPS and SmartUPS units) will drop the load at the > slightest power blip once the batteries go bad, while machines > connected directly to utility power will often ride out short blips. > It's especially insidious on the BackUPS units because the only way to > test the battery is to hit the test button and see if the load drops. > ;) These bargain-basement throw-away UPSes you mention are not the kinds of UPSes that give you power conditioning, and thus (I hope) obviously not the kinds of UPSes I meant. > > When I lived in a place that had a power outage once a week, I used a > UPS. Now that I live in a place where I get maybe one power outage a > *year*, I'm better off without out. I don't consider the ability to stay up for a few minutes when there's a brief blackout to be the most important function of a good UPS, even though that's kinda the reason the things were invented in the first place. The most important function of such a thing is power conditioning, which eliminates the problems of spikes and brownouts in the supply of power from the utility company even when nothing dramatic enough happens to actually crash a running machine right away. Such variability in power can be bad for both hardware and consistent, stable running of software. -- Chad Perrin [ original content licensed OWL: http://owl.apotheon.org ]