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I've built a new home server, based on Ubuntu Desktop 10.10 64bit. The Server is powered by an AMD X2 450e, 2GB DDR3/ECC, a 60GB 2.5" IDE system hard disk drive and three Samsung HD204UI 2TB hard disk drives for the Raid-Set. (4k sectors / Firmware is already updated)
Curious, but don't expect I have a write performance problem - the issue concerns to the read performance.
each drive got a partition (aligned - verified!)
file system is XFS / 128k chunks
# auto-create devices with Debian standard permissions
CREATE owner=root group=disk mode=0660 auto=yes
# automatically tag new arrays as belonging to the local system
# instruct the monitoring daemon where to send mail alerts
# definitions of existing MD arrays
ARRAY /dev/md0 level=raid5 num-devices=3 metadata=0.90 UUID=40e71bb8:4407168d:3e33e59e:db24ae34
input benchmark (raid volume is already filled up to 2TB):
dd if=/dev/zero of=/mnt/raid5/bonnie/4GB bs=1M count=4000
4000+0 Datensätze ein
4000+0 Datensätze aus
4194304000 Bytes (4,2 GB) kopiert, 26,908 s, 156 MB/s
time cp /mnt/raid5/bonnie/4GB /dev/null
real 1m3.519s => ~65MB/s
The benchmark results meet the results of smb transfers from and to my Windows 7 desktop PC. When I write to the server I can easily saturate the GbE connection with an avg. throughput of ~117MB/s (although the raid volume is already filled with ~2TB!). But when I transfer files form the server to my desktop I can't exceed ~80MB/s when I choose files even with files that are physically located on the outer sectors. At any given time the CPU is far away from fully utilization during the transfers. I've already played with several mount options but I can't get better results for the output.
Any suggestion is welcome!
Last edited by Orangutanklaus; 03-13-2011 at 04:11 AM.
Reason: Problem Solved
For comparison, here are my results on software-RAID0 over two Samsung F1 1TB (HD103UJ) drives, on a 94% full ext4 filesystem, run just now using the exact above commands.
My leftover extents are all at the very end of the disks, so I'm getting the very worst performance possible out of any new files.
Other than normal desktop usage, the drives were idle. Kernel is vanilla 126.96.36.199 + autogroup patches.
If you run the copy or write tests repeatedly, remember to remove the output file from the old run first.