[103501] in North American Network Operators' Group
Re: rack power question
daemon@ATHENA.MIT.EDU (Derek J. Balling)
Thu Apr 3 15:53:45 2008
Cc: nanog list <nanog@merit.edu>
From: "Derek J. Balling" <deballing@vassar.edu>
To: Michael Brown <michael@supermathie.net>
In-Reply-To: <47E978DF.7060906@supermathie.net>
Date: Thu, 3 Apr 2008 15:50:25 -0400
Errors-To: owner-nanog@merit.edu
--Apple-Mail-46--835724277
Content-Type: text/plain;
charset=US-ASCII;
format=flowed;
delsp=yes
Content-Transfer-Encoding: 7bit
Sorry to resurrect a slightly old thread, but I did want to touch on
something I noticed while catching up.
On Mar 25, 2008, at 6:12 PM, Michael Brown wrote:
> Naturally, that's redundant, so theoretical maximum usage per rack is
> half that, 23200W. Plus, the blades available today don't draw
> enough to
> fully load those power supplies. In the config I'm looking at now, a
> single blade (2x Quad-core 2GHz Intel, 4GB memory, no hard drives)
> draws
> 232W max, 160W lightly loaded. Let's pull a number of 195W out of the
> air to use.
Don't be so sure that's actually redundant. At $JOB->{prev}, we had a
fully populated IBM H chassis that had fully populated power supplies
where the chassis spent its entire life in an alarm state that there
was "insufficient power redundancy" ... the draw of the loaded chassis
(14 blades, 2 mgmt cards, 2 switches, 2 FC switches) was more than a
single "side" of power could handle. The chassis notified us that if
it lost a side of power it was going to throttle back the CPUs to
account for the loss.
So your theoretical maximum draw is NOT "1/2 the total"... in a nicely
populated chassis it will draw more than 1/2 the total and complain
the whole time about it.
Cheers,
D
--Apple-Mail-46--835724277
Content-Disposition: attachment;
filename=smime.p7s
Content-Type: application/pkcs7-signature;
name=smime.p7s
Content-Transfer-Encoding: base64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--Apple-Mail-46--835724277--
