On Sat, Mar 29, 2008 at 12:20 PM, Justin Piszcz <jpiszcz@xxxxxxxxxxxxxxx> wrote: <snip> > > Results: > http://home.comcast.net/~jpiszcz/20080329-raid/ > > I have gone back to my RAID 5 optimized configuration, I am done testing > for now :) > > __CREATION > 1. Test RAID 10 with no optimizations to the disks or filesystems. > a. mdadm --create /dev/md3 --assume-clean --chunk=256 --level=raid10 --raid-devices=10 --spare-devices=0 --layout=f2 /dev/sd[c-l]1 > b. mdadm --create /dev/md3 --assume-clean --chunk=256 --level=raid10 --raid-devices=10 --spare-devices=0 --layout=n2 /dev/sd[c-l]1 > c. mdadm --create /dev/md3 --assume-clean --chunk=256 --level=raid10 --raid-devices=10 --spare-devices=0 --layout=o2 /dev/sd[c-l]1 > 2. Test RAID 5 with no optimizations as well using the default layout. > a. mdadm --create /dev/md3 --assume-clean --chunk=256 --level=raid5 --raid-devices=10 --spare-devices=0 /dev/sd[c-l]1 > 3. Test RAID 5 with optimizations. > a. mdadm --create /dev/md3 --assume-clean --chunk=1024 --level=raid5 --raid-devices=10 --spare-devices=0 /dev/sd[c-l]1 > > __SETUP > 2. Format and set permissions and run benchmarks. > a. mkfs.xfs -f /dev/md3; mount /dev/md3 /r1; mkdir /r1/x > chown -R jpiszcz:users /r1 > > __TEST > 3. Run the following bonnie++ benchmark 3 times and take the average. > a. /usr/bin/time /usr/sbin/bonnie++ -d /x/test -s 16384 -m p34 -n 16:100000:16:64 > b. A script will be responsible for running it 3 times and the total time > of all runs will also be taken. > <snip> Thanks for sharing your benchmarking methods. I've been running similar benchmarks, trying to pick the best chunksize for my hardware, and I also found your previous thread "Fastest Chunk Size w/XFS For MD Software RAID = 1024k" in the archives. In my benchmarks[1], I see 256k & 128k giving the best results. So now I'm wondering if that's just because I have different harddrives (Seagate ST31000340NS 1000GB 32MB cache), or if the number of drives is also important - I only have 4 drives right now, but I plan on getting more when I can afford to. If I had more drives, would the larger chunksizes (512k or 1024k) be more likely to perform better than 256k? Also, would you be willing to share your script for averaging 3 bonnie++ runs? I'm too lazy to write my own, so I've just been doing single runs. [1] My bonnie++ results: <http://www.xmission.com/~beolach/bonnie++_4disk-ls.html> Thanks, Conway S. Smith -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
