[Beowulf] Re: real hard drive failures

Mark Hahn hahn at physics.mcmaster.ca
Mon Jan 31 11:14:43 PST 2005

> <another view>
> and the other view point is "fans" is the insurance policy that
> the disks will last longer than if it didnt have the fans
> </view>

sounds like putting mudflaps and a cattle bar on a city-SUV.

I just don't see disks dissipating enough heat to make them worthy 
of their own fan(s), considering that this could reduce the system MTBF
by a good chunk (say, 1/3) and that it's easy to put disks into the 
chassis's airflow.

> fans failing is cheap compared to disks dying

but fans failing will *cause* disks to die.  that's really the crux 
of the argument against more fans.

> "spinning didks" is a dead market ... 
> 	- remember, ibm sold off that entire division to hitachi
> 	so their days are number ... which also obvious from watching
> 	how cheap 1GB and 2GB compact flash is  and it's just a matter
> 	of time before it's 100GB CFs but is it fast enuff .. 
> 	1GB/sec sustained data transfer

yeah, and the world needs 5 computers.  flash and disks are both on a 
2d-shrink curve, with no end in sight for either one.  it's hard to see
why flash would suddenly chage its curve (even if there are 16 300mm 
fabs under construction...)

from a quick look at pricewatch, 2G flash costs $108 (there's a listing
for 2.2G at $89, but it's a microdisk!)  

that's $54/GB, versus $0.4/GB for disk ($64/160G).  I don't think
flash is going to improve by a factor of 100 any time soon.

on that note, though - does anyone have comments about booting 
machines from flash?

> and disks should NOT fail before the power supply or fans ..

right, disks "should" fail shortly after the fans ;)

More information about the Beowulf mailing list