[Beowulf] real hard drive failures

[Pete Lancashire]

The nice thing and about the only nice thing about using
a fan is in this case, the failure of a fan is not going
to kill you. If your mother board has a 3-wire fan 'port'
not used you can have it report failure.

In the past I've built using a 8pin MicroChip a simple
failure detector. I would think with some imagination
you could take a 555 + transistor + pizo buzzer and
create a simple alarm.

Another thing to use but I've not seen as an individual
item is a heat sink. The Sun SPUD brackets come with a
plate that attaches to the bottom of the drive, the plate
has been punched with hmmm .. louvers ?.

-pete "ah the days of so many fans you could not hear yourself talk"

On Tue, 2005-01-25 at 14:26, Mark Hahn wrote:
> > > I'm only partially interested in the thread "Cooling vs HW replacement" but 
> > > the problem with drive failures is a real pain for me. So, I thought I'd 
> > > share some of my experience.
> > 
> > i'd add 1 or 2 cooling fans per ide disk, esp if its 7200rpm or 10,000 rpm
> > disks 
> 
> I'm pretty dubious of this: adding two 50Khour moving parts to 
> improve the airflow around a 1Mhour moving part which only dissipates
> 10W in the first place?  designing the chassis for proper airflow 
> with minimum fanage is obviously smarter and probably safer.
> 
> > 	- if downtime is important, and should be avoidable, than raid
> > 	is the worst thing, since it's 4x slower to bring back up than
> > 	a single disk failure
> 
> eh?  you have a raid which is not operational while rebuilding?
> 
> > 	- raid will NOT prevent your downtime, as that raid box
> > 	will have to be shutdown sooner or later 
> > 	( shutting down sooner ( asap )  prevents data loss )
> 
> huh?  hotspares+hotplug=zero downtime.
> 
> but yes, treating whole servers as your hotspare+hotplug element is 
> a nice optimization, since hotplug ethernet is pretty cheap vs 
> $50 hotplug caddies for each and every disk ;)
> 
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