[Lustre-discuss] RPC limitation

[Jeffrey Bennett]

Andreas and Oleg,

Sorry to bother you again.

Is there any way to "force" an RPC page size of 256kb and pack several 4kb random operations into a 256k page so the final throughput can increase?

Thanks

Jeffrey A. Bennett
HPC Systems Engineer
San Diego Supercomputer Center
http://users.sdsc.edu/~jab

-----Original Message-----
From: Andreas.Dilger at sun.com [mailto:Andreas.Dilger at sun.com] On Behalf Of Andreas Dilger
Sent: Friday, March 05, 2010 2:05 AM
To: Jeffrey Bennett
Cc: Oleg.Drokin at Sun.COM; lustre-discuss at lists.lustre.org
Subject: Re: [Lustre-discuss] One or two OSS, no difference?

On 2010-03-04, at 14:18, Jeffrey Bennett wrote:
> I just noticed the sequential performance is ok, but the random IO  
> (which is what I am measuring) is not. Is there any way to increase  
> random IO performance on Lustre? We have LUNs that can provide  
> around 250.000 random read 4kb IOPS but we are only seeing 3.000 to  
> 10.000 on Lustre.

There is work currently underway to improve the SMP scaling  
performance for the RPC handling layer in Lustre.  Currently that  
limits the delivered RPC rate to 10-15k/sec or so.