nanog mailing list archives

Re: Power cut if temps are too high


From: Owen DeLong <owen () delong com>
Date: Tue, 28 May 2019 19:56:26 -0700

It’s unlikely to apply to much of anything in a datacenter other than disks.

The reason it applies to disks is because rapid cooling of a drive will lead to uneven cooling of the platters which 
may cause abnormal stresses leading to shattering and/or warpage (depending on the material the drive platters are made 
from).

Most electronic components can tolerate a pretty steep thermal curve in either direction so long as the curve doesn’t 
take them out of spec one way or the other.

Also, most circuit boards and the like do not have enough mass to surface area ratio to lead to significant temperature 
differentials within a small physical distance.

Owen


On May 28, 2019, at 12:18 , bzs () theworld com wrote:


Something to keep in mind is that some equipment, disks in particular,
should only be cooled at a certain rate once they're hot, often
annoyingly slow by the specs like 2-3 degrees C per hour but there are
probably circuits sensitive to this also which could be anywhere.

It came up because it happened to me in Cambridge, MA in the dead of
winter and every helpful person in the building came by to suggest I
just open windows and doors to the snowy outdoors to get things
running sooner.

It should be in the specs and if you're concerned about equipment
running in too hot an environment you might be concerned about this
also. Particularly after a forced power-down which also powers down
equipment fans while the chips etc are still hot so will continue
heating cases.

Ambient air temperature might not be telling you the whole story is
the point.

I keep one of those big 5' fans, looks like something they use in
Hollywood for windstorms and feels a bit like it on high, for just
this sort of reason tho even if I just think it's getting warm, and
several smaller fans to point at racks etc.

The best thing you can do if it gets too hot is keep the air moving.

(Where to plug the fans in after a power shutdown is your problem, I
knew someone would think that!)

-- 
       -Barry Shein

Software Tool & Die    | bzs () TheWorld com             | http://www.TheWorld.com
Purveyors to the Trade | Voice: +1 617-STD-WRLD       | 800-THE-WRLD
The World: Since 1989  | A Public Information Utility | *oo*


Current thread: