On 2010-03-09, at 17:40, Jeffrey Bennett wrote: > 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?
As Oleg mentioned, Lustre will in fact pack up to 256 random 4kB writes into a single RPC/RDMA over the network, IFF they are for the same object. There is the long-standing bug 988 that relates to packing multiple small writes for different objects on the same OST into a single RPC/ RDMA request, but there was never enough demand to finish it. > -----Original Message----- > From: andreas.dil...@sun.com [mailto:andreas.dil...@sun.com] On > Behalf Of Andreas Dilger > Sent: Friday, March 05, 2010 2:05 AM > To: Jeffrey Bennett > Cc: oleg.dro...@sun.com; lustre-discuss@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. > Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. _______________________________________________ Lustre-discuss mailing list Lustre-discuss@lists.lustre.org http://lists.lustre.org/mailman/listinfo/lustre-discuss