From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Tokarev Subject: Re: raid10: unfair disk load? Date: Fri, 21 Dec 2007 23:56:09 +0300 Message-ID: <476C2869.1080903@msgid.tls.msk.ru> References: <476BA4FD.6080401@msgid.tls.msk.ru> <476BA942.40406@msgid.tls.msk.ru> <20071221174902.6fc02c4e@absurd> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20071221174902.6fc02c4e@absurd> Sender: linux-raid-owner@vger.kernel.org To: Janek Kozicki Cc: Linux RAID List-Id: linux-raid.ids Janek Kozicki wrote: > Michael Tokarev said: (by the date of Fri, 21 Dec 2007 14:53:38 +0300) > >>> I just noticed that with Linux software RAID10, disk >>> usage isn't equal at all, that is, most reads are >>> done from the first part of mirror(s) only. > > what's your kernel version? I recall that recently there have been > some works regarding load balancing. It was in my original email: > The kernel is 2.6.23 but very similar behavior is > shown by earlier kernels as well. Raid10 stripe > size is 256Mb, but again it doesn't really matter > other sizes behave the same here. Strange I missed the new raid10 development you mentioned (I follow linux-raid quite closely). Lemme see... no, nothing relevant in 2.6.24-rc5 (compared with 2.6.23), at least git doesn't show anything interesting. What change(s) you're referring to? Thanks. /mjt