[Lustre-discuss] Performance parameters

Enrico Morelli
Wed, 11 Jun 2008 14:16:06 -0000

On Wed, 11 Jun 2008 08:54:41 -0400
"Brian J. Murrell" <Brian.Murrell at Sun.COM> wrote:

> On Wed, 2008-06-11 at 09:49 +0200, Enrico Morelli wrote:
> >
> > The lustre server (MDS and OSS) is an HP DL380 G5 (Dual Xeon 5130
> > 2GHz, 2GB RAM) connected through an HP P800 Sata/SAS controller to
> > an HP MSA60 storage equipped with 7x500GB SATA disk in RAID 6.
>
> So you have one single RAID6 volume that you have sliced up for the
> MDT and OSTs?
>
> That configuration is going to provide a lot of contention between the
> MDT and OSTs as you have created a single "device" for everything
and
> are losing out on the possibilities of parallelism.
>
> Lustre''s ability to shine depends on it''s components
having dedicated
> access to discrete devices so that it can exploit the parallelism of
> them.
>
> Lustre also shines in very scalable, high throughput situations.  It
> is not optimized for the "lots of small files" situation.  Lots
of
> memory for caching is your best bet in the "lots of small files"
and
> 2GB of RAM for the MDS and OSS are not very much.
>
> Can I ask why you chose Lustre as a solution to provide file service
> to a single RAID6 volume of only 7 disks @ 3.5TB on a single server?
> Lustre really is not going to shine in that configuration.
>

Because we thought that Lustre was better than NFS and more scalable
also in a simple configuration like our.

Now, if I reduce the OSTs to one do you think that I can improve the
performance?

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