Date: Fri, 15 Jun 2012 17:54:14 -0600 From: Chad Perrin <perrin@apotheon.com> To: freebsd-questions@freebsd.org Subject: Re: Uptime [OT] Message-ID: <20120615235414.GA15957@hemlock.hydra> In-Reply-To: <CAHhngE1CudsAb_OHzagSOAkFrMN3ak=7rvANKdBRuXedF%2BaW3Q@mail.gmail.com> References: <op.wfxecjm234t2sn@cr48.lan> <201206151249.q5FCnnKF019002@mail.r-bonomi.com> <20120615160005.GB20814@hemlock.hydra> <CAHhngE1CudsAb_OHzagSOAkFrMN3ak=7rvANKdBRuXedF%2BaW3Q@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, Jun 15, 2012 at 11:47:55PM +0000, David Brodbeck wrote: > On Fri, Jun 15, 2012 at 4:00 PM, Chad Perrin <perrin@apotheon.com> 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 ]
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20120615235414.GA15957>