Messages in this thread | | | Date | Wed, 28 May 2008 12:54:11 +0200 | From | Peter Rabbitson <> | Subject | Re: Performance Characteristics of All Linux RAIDs (mdadm/bonnie++) |
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Justin Piszcz wrote: > Hardware: > > 1. Utilized (6) 400 gigabyte sata hard drives. > 2. Everything is on PCI-e (965 chipset & a 2port sata card) > > Used the following 'optimizations' for all tests. > > # Set read-ahead. > echo "Setting read-ahead to 64 MiB for /dev/md3" > blockdev --setra 65536 /dev/md3
That's actually 65k x 512byte blocks so 32MiB
> # Set stripe-cache_size for RAID5. > echo "Setting stripe_cache_size to 16 MiB for /dev/md3" > echo 16384 > /sys/block/md3/md/stripe_cache_size > > # Disable NCQ on all disks. > echo "Disabling NCQ on all disks..." > for i in $DISKS > do > echo "Disabling NCQ on $i" > echo 1 > /sys/block/"$i"/device/queue_depth > done > > Software: > > Kernel: 2.6.23.1 x86_64 > Filesystem: XFS > Mount options: defaults,noatime > > Results: > > http://home.comcast.net/~jpiszcz/raid/20080528/raid-levels.html > http://home.comcast.net/~jpiszcz/raid/20080528/raid-levels.txt > > Note: 'deg' means degraded and the number after is the number of disks > failed, I did not test degraded raid10 because there are many ways you > can degrade a raid10; however, the 3 types of raid10 were benchmarked > f2,n2,o2. > > Each test was run 3 times and averaged--FYI. >
Results are meaningless without a crucial detail - what was the chunk size used during array creation time? Otherwise interesting test :)
Cheers
Peter
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