[Discuss] Storage question follow-up

[bogstad at pobox.com (Bill Bogstad)]

On Fri, Feb 22, 2013 at 1:08 PM, Dan Ritter <dsr at randomstring.org> wrote:
> On Fri, Feb 22, 2013 at 01:05:55PM -0500, Bill Bogstad wrote:
>>   That's close to 50 million 4GByte video files.   Here's their blog
>> entry about it:
>>
>> http://blog.backblaze.com/2013/02/20/180tb-of-good-vibrations-storage-pod-3-0/
>
> Note that backblaze does all their redundancy on a cross-pod
> basis, not inside a pod. Their model is that any pod can fail
> without disturbing the overall system. As a result, they don't
> do hotswap or RAID, and they don't care much about performance.

It does look like BackBlaze's  hardware probably doesn't do hotswap.
However, even if they don't use it, he could always do software RAID.
In fact, it sounds like they use software RAID6 with LVM.   Or at
least they did the in the second iteration of their storage pods:

http://blog.backblaze.com/2011/07/20/petabytes-on-a-budget-v2-0revealing-more-secrets/

As for performance, I seem to recall that last night Peter said that
once a file is "in place"; it doesn't move around very much.  So
performance doesn't sound like the primary issue.

Bill Bogstad