Re: filesystem benchmarking fun

On Wed, May 16, 2007 at 08:12:09PM +0200, Jan Engelhardt wrote:

On May 16 2007 10:42, Chris Mason wrote:

For example, I'll pick on xfs for a minute. compilebench shows the
default FS you get from mkfs.xfs is pretty slow for untarring a bunch of
kernel trees.

I suppose you used 'nobarrier'? [ http://lkml.org/lkml/2006/5/19/33 ]

Oddly, xfs fails barriers on this sata drive although the other filesystems
don't. But yes, I tried both ways.


Dave Chinner gave me some mount options that make it
dramatically better,

and `mkfs.xfs -l version=2` is also said to make it better

I used mkfs.xfs -l size=128m,version=2
mount -o logbsize=256k,nobarrier


but it still writes at 10MB/s on a sata drive that
can do 80MB/s. Ext3 is better, but still only 20MB/s.

Both are presumably picking a reasonable file and directory layout.
Still, our writeback algorithms are clearly not optimized for this kind
of workload. Should we fix it?

Also try with tmpfs.

Sorry, I'm not entirely clear on what we learn from trying tmpfs?

-chris

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