From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Clements Subject: Re: does chunksize matter in raid-1? Date: Sat, 06 Aug 2005 08:44:49 -0400 Message-ID: <42F4B0C1.1080306@steeleye.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: jeff@jab.org Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Jeff Breidenbach wrote: > Does chunk size matter *at all* for RAID-1? > > mdadm --create /dev/md0 --level=1 --chunk=8 /dev/sdc1 /dev/sdd1 > mdadm --create /dev/md0 --level=1 --chunk=128 /dev/sdc1 /dev/sdd1 > > In my mental model of how RAID works, it can't possibly matter > what my chunk size is whether I've got 1KB files or 1GB files because > no striped reading occurs. > > Is my mental model wrong? No, chunk size does not matter for raid1. In fact, some/most? kernels will print a message to that effect if you specify a chunk size for a raid1 array. -- Paul