[Lustre-discuss] state of sun x4500 drivers

[Frank Leers]

I'd like to offer to debunk some of this...

There are plenty of thumpers (x4500) out there in the wild deployed as
OSSes under lustre.  During a recent deployment using the driver that
was mentioned in another post in this thread, the average single disk
observed performance was just over 60MB/s with sequential 256k reads.  

Here's the link to the mv_sata driver, but as you mention you will need
to vary from the stock RPM's and venture into custom kernel-land.

http://www.sun.com/servers/x64/x4500/downloads.jsp

We see close to 1GB/s from a single thumper over IB.  Your bottleneck
will definitely be the bonded gigE, and you will be leaving performance
on the table.

-fank

On Wed, 2008-04-23 at 13:05 -0400, Brock Palen wrote:
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> Thats disappointing, thanks for the input though.  The paper at:
> http://wiki.lustre.org/images/7/79/Thumper-BP-6.pdf
> 
> Points out how to patch it to enable that functionality, but we want  
> to keep with the CFS stock kernel.
> 30MB/s  might be fine for us,  we only plan on bonding the 4 thumber  
> 1Gig-e  interfaces.
> 
> Brock Palen
> www.umich.edu/~brockp
> Center for Advanced Computing
> brockp at umich.edu
> (734)936-1985
> 
> 
> 
> On Apr 23, 2008, at 1:00 PM, Brian Behlendorf wrote:
> >
> > Recently I have also been doing some linux work with the x4500 and  
> > I have been
> > using the sata_mv driver (v0.81).  The driver will properly detect  
> > all the
> > drives and you may access them safely.  However, from what I've  
> > seen the
> > driver needs some further development work to actually perform  
> > well.  I see
> > only 30 MB/s write rates to a single disk using a simple streaming  
> > dd test.
> > Much of this bad performance may simply be due to the fact that the  
> > driver
> > can not enable the disk write-back cache forcing you to use write- 
> > thru mode.
> >
> > So currently the bottom line is linux will work on the x4500.  But  
> > to get it
> > working well someone is going to need to invest some development  
> > effort to
> > improve the linux driver.
> >
> > Good luck,
> > Brian
> >
> >
> >> There was some discussion about the driver/module for the sata
> >> controlers in the thumper (x4500) in the linux kernel.
> >>
> >> My question is if we bought one of these,  would the CFS kernel have
> >> everything needed to use the thumper in a safe way.
> >> Thank You.
> > _______________________________________________
> > Lustre-discuss mailing list
> > Lustre-discuss at lists.lustre.org
> > http://lists.lustre.org/mailman/listinfo/lustre-discuss
> 
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