[kwlug-disc] [OT] linux server power

Unsolicited unsolicited at swiz.ca
Fri Jan 28 16:50:39 EST 2011

On Fri, January 28, 2011 12:29 am, Rashkae wrote:
> On 11-01-27 08:08 PM, Insurance Squared Inc. wrote:
>> OK, I slid the linux part in there :).

Not needed. The list is as much about 'K-W' and computers as much as it is
about Linux, particularly as there is recognition that we live in a
Windows world.

Power, and its consumption, affects everything above.

>> My wife just brought in an electrician to tell us why our electricity
>> costs at home are so high.  He came up with a bunch of different
>> things, but one of the potential culprits are the two computers
>> running in the basement.  One's an old Dell tower server that runs our
>> Voip phones.  The other is a web/database/backup server running on an
>> older HP workstation.
>> A quick back of the napkin estimate from the electrician indicated the
>> two machines might be costing me 30+ bucks a month in hydro alone.
> Did this electrician use a simple Watt meter before making these napkin
> calculations?   Unless these two computers have attached CRT's turned on
> 24/7, I would be *really* surprised if combined these are using more
> than 150W, (3.6 KWh / day, * 30 = 108KWh)  Still worth reducing, of
> course, but that should cost less than half than this $30 estimate.

Or whatever the doohickey attached to a VOM is that looks like a clamp
from an operating room table, that tells you the power flowing through the
wires via inductance?

Check my math please. 500W = 1/2 kW @ $0.06/kWh -> 0.5 x $0.06 x 24 * 30 =
$21.60 for a 500W power supply on a computer running full bore 24 x 7.

    You can't be drawing more or your power supply would fall over, and
you can't be drawing anywhere near 80% or it would reasonably quickly
melt. In either case, ain't nothing happening here in those cases
(it's dead, Jim). So call it $17.28.

Leveraging off what John said, and what he's said in the past (which was
based on his best guess and/or experience of the time), if your VoIP
hardware is all external/IP, through ATAs and/or SPAs, then a VM should be
OK. Further, being a vm, and since you are of course running two redundant
failover systems in your home bet your business environment, you can
snapshot the vm occasionally, so that if you're in the midst of a problem,
you fire up the latent vm on the other machine. Arguably, this is true of
your web server as well - especially if the non-static pages it's pulling
are off another computer, such as that old laptop doing nothing any more.
[I'd bet Khalid could speak to the viability of that, here - you might
want to post how many lines and phones you're running on VoIP, and per day
hits, simultaneous users, extent of dynamic content you're serving up on
the web, to get more precise fuzzy suggestions here.)

What's your tolerance for down time, and what's your service people
proximity like? If they can have you going within 4 hours, do you even
need a backup voip solution if merely being able to pick up the ringing
phone is sufficient.

Would an Unlimitel Virtual PBX suit you, and take the on-site hardware
issue away entirely? Or a local hosting provider?

If your needs are modest enough, Lori has demonstrated Asterisk on a
LinkSys. And if not modest enough, only slightly bigger hardware would do
it. Same may be true for a webserver, depending upon the amount of dynamic
content, perhaps utilizing space coming off a USB drive.

Re: SSD's ... is it not still current thinking that SSD's have a shorter
lifespan than hard drives?

And don't forget, if you have > 0.5 TB drives now, I don't believer there
are may SSD's of that size out there, and certainly no SSD is reasonably
priced, vis a vis hard drive, using capacity as your only yardstick.

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