XFS: Abysmal write performance because of excessive seeking (allocation groups to blame?)

[Geoffrey Wehrman]

On Fri, Apr 06, 2012 at 06:28:37PM -0500, Stan Hoeppner wrote:
| So while the XFS AG architecture may not be perfectly suited to your
| single 6 drive RAID6 array, it still gives rather remarkable performance
| given that the same architecture can scale pretty linearly to the
| heights above, and far beyond.  Something EXTx and others could never
| dream of.  Some of the SGI guys might be able to confirm deployed single
| XFS filesystems spanning 1000+ drives in the past.  Today we'd probably
| only see that scale with CXFS.

With an SGI IS16000 array which supports up to 1,200 drives, filesystems
with large numbers of drives isn't difficult.  Most configurations
using the IS16000 have 8+2 RAID6 luns.  I've seen sustained 15 GB/s to
a single filesystem on one of the arrays with a 600 drive configuration.
The scalability of XFS is impressive.


-- 
Geoffrey Wehrman
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