Re: Ceph Write Path Improvement

[Mark Nelson <mnelson@redhat.com>]

On 09/03/2015 11:23 AM, Robert LeBlanc wrote:
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> Somnath,
>
> I'm having a hard time with your slide deck. Am I understanding
> correctly that the default Hammer install was performed on SSDs with
> co-located journals, but the optimized code was performed on the same
> SSDs but the journal was in NVRAM? If so I'm having a hard time
> understanding how these tests can be comparable. I really like the
> performance gains you are seeing, but I'm trying to understand how
> much the optimized code alone helps performance.

Hi Robert,

We talked about this a bit at the weekly performance meeting.  I think 
Somnath just hasn't gotten a chance to do those tests yet and is 
planning on doing them in the coming weeks.  I believe he started out 
with hammer on the SSDs and then tried to figure out how to tweak things 
to make the NVRAM configuration perform better.  Now he has to go back 
and retest the original configuration but with the new code.

Mark