I'm not a database expert, but are you sure you are using RDMA? AFAIK mysql just uses TCP/IP which is a lot slower.
On Sep 13, 2012, at 1:52 PM, hol...@th.physik.uni-frankfurt.de wrote: > Hi, > > I am a bit confused. > > I have 4 top notch dual socket machines with 128GB ram each. I also > have a > Nexenta box which is my NFS / ZFS server. Everything is connected > together > with QDR infiniband. > > I want to use this for setup for mysql databases so I am testing > for 16K > random and stride performance. > > If I set up a single machine to hammer the fileserver with IOzone I > see > something like 50,000 IOPS but if all four machines are hammering the > filesystem concurrently we got it up to 180,000 IOPS. > > Can anyone tell me what might be the bottleneck on the single > machines? > Why can I not get 180,000 IOPS when running on a single machine. > > If I test using IPoIB in connected mode I see this: http:// > pastie.org/4708542 > > Some kind of buffer problem? > > Thanks, > > Andrew > > > > > _______________________________________________ > Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin > Computing > To change your subscription (digest mode or unsubscribe) visit > http://www.beowulf.org/mailman/listinfo/beowulf _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
