[Lilug] query: handling exponentially increasing storage requirements on a rack

[Chris Knadle]

On 07/01/2015 09:35 AM, Cholewa, John wrote:
> So I ordered a 36-drive, >250 TB nfs storage server for my lab. I would 
> have preferred avoiding needing to deal with drives that I'd normally 
> consider too new for use in this environment (they're 8 TB each), but 
> I've been limited by our heavy requirements.  The vendor is having 
> difficulty in getting this large amount of space to behave as a single 
> xfs mount point.  I may have to accept hacks along the line of splitting 
> up the array to multiple volumes.

I've been investigating hardware for a small home storage server and the
8 TB drives seem worrisome to me; they're all either SMR (Shingled
Magnetic Recording) drives that have some odd write timing
characteristics or helium-filled drives.  Helium is such a small
molecule that it slowly leaks through metal, so I have some concerns
about the long-term reliability of these drives.  Because of these
concerns I've decided to stick with 6 TB drives that use a more
conventional design.

> Some of the people on this list are at much larger labs, wherein pithily 
> small storage amounts like a mere quarter petabyte are easily laughed 
> off as chumpspace.  While I can't change what I'm getting here this time 
> around, I wouldn't mind hearing what kind of solutions are used to get 
> large amounts of storage to look like single mounts for end-user 
> researchers and the like.  Do you cluster your storage among multiple 
> computers and transparently make them look like a single server?  If so, 
> what are some good practice routes towards achieving this?  I know that 
> there are alternate means of doing storage over a network, so right now 
> I'm definitely reaching the limits of my old-school way of thinking and 
> wouldn't mind some pokes in the right direction.  :)

This does sound like you've hit the limits of a single-box solution.
This probably points to needing some kind of clustering filesystem to
clump together several machines like GFS2, GlusterFS, OCFS2, GPFS.
[Or at least that's what I'd be researching if I was dealing with this
issue myself.]

   -- Chris

-- 
Chris Knadle
Chris.Knadle at coredump.us