[Beowulf] PetaBytes on a budget, take 2

[Ellis H. Wilson III]

On 07/21/11 12:09, Eugen Leitl wrote:
> On Thu, Jul 21, 2011 at 11:45:28AM -0400, Douglas Eadline wrote:
>> I'm curious, has anyone tried building one of these or know
>> of anyone who has?
>>
>> Seems like a cheap solution for raw backup.

I have doubts about the manageability of such large data without complex
software sitting above the spinning rust to enable scalability of
performance and recovery of drive failures, which are inevitable at this
scale.

I mean, what is the actual value of this article?  They really don't
tell you "how" to build reliable storage at that scale, just a
hand-waving description on how some of the items fit in the box and a
few file-system specifics.  THe SATA wiring diagram is probably the most
detailed thing in the post and even that leaves a lot of questions to be
answered.

Either way, I think if someone were to foolishly just toss together
>100TB of data into a box they would have a hell of a time getting
anywhere near even 10% of the theoretical max performance-wise.  Not to
mention double-disk failures (not /that/ uncommon with same
make,model,lot hdds) would just wreck all their data.

Now for Backblaze (which is a pretty poor name choice IMHO), they manage
all that data in-house so building cheap units makes sense since they
can safely rely on the software stack they've built over a couple years.
 For traditional Beowulfers, spending a year or two developing custom
software just to manage big data is likely not worth it.

ellis