From mboxrd@z Thu Jan 1 00:00:00 1970 From: Asdo Subject: Re: single cpu thread performance limit? Date: Fri, 12 Aug 2011 14:48:23 +0200 Message-ID: <4E452117.9060300@shiftmail.org> References: <4E44265D.3050809@hardwarefreak.com> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-reply-to: Sender: linux-raid-owner@vger.kernel.org To: mark delfman Cc: Stan Hoeppner , Linux RAID Mailing List , NeilBrown List-Id: linux-raid.ids On 08/11/11 21:37, mark delfman wrote: > So, a single RAID10 creates a single thread - which will max at maybe 200K IOPS. > Create 4 x RAID10's seems OK, but they will not scale so great with a > RAID0 on top :( > Ideal would be a few threads per RAIDx Try this: LVM. AFAIR, LVM does not have its thread, it is the application thread that executes LVM code. This should not impede scalability. If you are testing with something like fio, which randomly spans the whole device with random I/O during test, you can use a linear LVM concatenation (which is the default when you create a LV that spans the whole VG). Otherwise use striping on lvcreate. Try both if possible. Also, as other people have said, your kernel is quite old... Actually I don't remember if there were performance improvements regarding what you are doing, but you probably should try a newer one. Let me know how it goes.