Uptime [OT]

Chad Perrin perrin at apotheon.com
Fri Jun 15 23:54:15 UTC 2012

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 at 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 ]

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