[Lustre-discuss] Performance Regression in 1.6.5 ?

[Andreas Dilger]

On Jul 11, 2008  16:46 -0400, Roger Spellman wrote:
> I'm seeing a performance regression for Writes in 1.6.5 relative to
> 1.6.4.3.  However, I'm also seeing a performance improvement for reads.
> I'm running over Mellanox IB fabric.  Is anyone else seeing this? 
> 
>  
> 
> Here are some numbers for my HW:
> 1.6.4.3 + ofed 1.3:    Writes 390 MB/s,  Reads 369 MB/s
> 
> 1.6.5   + ofed 1.3.1:  Writes 366 MB/s,  Reads 437 MB/s
> 
> Has anyone else taken performance measurements?

There was one similar thread on the list...  Did you try turning off the
checksumming?  That is again on by default in 1.6.5, with an improved
algorithm, but can be disabled at runtime on the clients with:

	lctl set_param osc.*.checksums=0

or permanently on the MGS (MDS) with:

	lctl conf_param {fsname}.osc.checksums=0


Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.