Reducing ZFS blocksize to improve Cyrus write performance ?

[Vincent Fox]

On Mon, 2010-08-09 at 17:22 +0200, Eric Luyten wrote:
> Folks,
> 
>  did you consider, measure and/or carry
> out a change of the default 128 KB blocksize ?

To more directly answer your question than last post...

We did some testing with Bonnie++ prior to deployment
and changing recordsize didn't reveal any particular
improvement for what we guessed represented simulation.

After deployment we ran into performance problems, which
turned out to be related to fsync "corner" in then-current
release, later fixed in a patch.  We ran a performance
tool from Sun which clearly showed the problem with fsync
but I can't recall it's name right now.  We were in production
though at that point and not free to vary recordsizes and
see the effect with that tool.