From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Rabbitson Subject: Re: Performance Characteristics of All Linux RAIDs (mdadm/bonnie++) Date: Wed, 28 May 2008 12:54:11 +0200 Message-ID: <483D39D3.4020906@rabbit.us> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Justin Piszcz Cc: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, xfs@oss.sgi.com List-Id: linux-raid.ids 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