>>> On Fri, 18 Nov 2005 15:16:51 -0500 (EST), Jon Lewis
>>> <jlewis@xxxxxxxxx> said:
[ ... the legendary :-) 120-300TB filesystem ... ]
jlewis> One fs this large seems like a recipe for trouble.
It is a ''where angels fear to tread'' situation. :-)
However, whether one decides to store 300TB as a single fs or
rather some less ''optimistic'' way, the sheer amount of data
involved requires a massive underlying storage and backup (never
mind _offsite_ backup) system.
300GB drives are around 2^38B, and 300TB are around 2^48. This
means that one probably is looking at a storage system with
around 4*2^(48-38) drives, that is around 4,000 drives (and that
factor of 4 is probably a conservative one, in most cases I'd be
more comfortable with a factor of 6).
jlewis> What are you planning on storing?
That's a good question, but it is not even the biggest problem;
just the amount of data and of hardware needed to store it are
a bigger issue (and I laughed when I read the ''concat of thin
RAID5s SANs''), never mind what the data looks like and how it
should be stored.
I think indeed that a team of experienced large storage system
consultants analyzing in depth the whole situation that gives
rise to a 300TB storage problem should be looking at it...