On Thu, 2006-05-18 at 10:04 +0200, Nicholas C. Strugnell wrote: > On Thu, 2006-05-18 at 08:44 +0100, Bob Gautier wrote: > > On Thu, 2006-05-18 at 02:25 -0500, Jonathan E Brassow wrote: > > > The system bus isn't a limiting factor is it? 64-bit PCI-X will get > > > 8.5 GB/s (plenty), but 32-bit PCI 33MHz got 133MB/s. > > > > > > Can your disks sustain that much bandwidth? 10 striped drives might get > > > better than 200MB/s if done right, I suppose. > > > > > It might make sense to test raw writes to a device with dd and see if > that gets comparable performance figures - I'll just try that myself > actually. write throughput to EVA 8000 (8GB write cache), host DL380 with 2x2Gb/s HBAs, 2GB RAM testing 4GB files: on filesystems: bonnie++ -d /mnt/tmp -s 4g -f -n 0 -u root ext3: 129MB/s sd=0.43 ext2: 202MB/s sd=21.34 on raw: 216MB/s sd=3.93 (dd if=/dev/zero of=/dev/mpath/3600508b4001048ba0000b00001400000 bs=4k count=1048576) NB I did not have exclusive access to the SAN or this particular storage array - this is a big corp. SAN network under quite heavy load and disk array under moderate load - not even sure if I had exclusive access to the disks. All values averaged over 20 runs. The very low deviation of write speed on ext3 vs. exr2 or raw is interesting - not sure if it means anything. In any case, we don't manage to get very close to the theoretical throughput of the 2 HBAs, 512MB/s Nick -- M: +44 (0)7736 665171 Skype: nstrug http://europe.redhat.com GPG FPR: 9C6C 093C 756A 6C57 49A1 E211 BBBA F5F5 C440 5DE0
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