On Sun, Feb 03, 2013 at 01:36:48PM -0700, rkj@xxxxxxxxxxxx wrote: > > I am working with hardware RAID0 using LSI 9271-8i + 8 SSD's. I am > using CentOS 6.3 on a Supermicro X9SAE-V motherboard with Intel Xeon > E3-1275V2 CPU and 32GB 1600 MHz ECC RAM. My application is fast > sensor data store and forward with UDP based file transfer using > multiple 10GbE interfaces. So I do not have any concurrent loading, > I am mainly interested in optimizing sequential read/write > performance. > > Raw performance as measured by Gnome Disk Utility is around 4GB/s > sustained read/write. I don't know what that does - probably lots of concurrent IO to drive deep queue depths to get the absolute maximum possible from the device.... > With XFS buffer IO, my sequential writes max > out at about 2.5 GB/s. CPU bound on single threaded IO, I'd guess. > With Direct IO, the sequential writes are > around 3.5 GB/s but I noticed a drop-off in sequential reads for > smaller record sizes. Almost certainly IO latency bound on single threaded IO. > I am trying to get the XFS sequential > read/writes as close to 4 GB/s as possible. Time to go look up how to use async IO or multithreaded direct IO. FWIW, the best benchmark is your application - none of what you've talked about even come close to modelling the data flow a network-disk-network store-and-forward system needs, and a data rates of 4GB/s you are going to benchmark the network devices flowing data at the same time you do disk IO.... > I have documented all of the various mkfs.xfs options I have tried, > fstab mount options, iozone results, etc. in this forum thread: Configuration changes won't make any difference to data IO latency or CPU usage. IOWs, SSDs don't magically solve the problem of having to optimise the way the applications/benchmarks do IO and so no amount of tweaking the filesystem will get you to your goal if the application is deficient... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
