From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Rabbitson Subject: Re: Raid1 replaced with raid10? Date: Mon, 07 May 2007 08:49:25 +0200 Message-ID: <463ECBF5.7030206@rabbit.us> References: <45FF1BDF.6060304@rabbit.us> <463B2D15.7020305@rabbit.us> <463B4C4F.9030504@tmr.com> <17982.42974.461499.127486@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <17982.42974.461499.127486@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Neil Brown wrote: > On Friday May 4, davidsen@tmr.com wrote: >> Peter Rabbitson wrote: >>> Hi, >>> >>> I asked this question back in march but received no answers, so here it >>> goes again. Is it safe to replace raid1 with raid10 where the amount of >>> disks is equal to the amount of far/near/offset copies? I understand it >>> has the downside of not being a bit-by-bit mirror of a plain filesystem. >>> Are there any other caveats? >>> > > To answer the original question, I assume you mean "replace" as in > "backup, create new array, then restore". > You will get different performance characteristics. Whether they > better suit your needs or not will depend largely on your needs. Hi Neil, Yes I meant take an existing 2 drive raid1 array (non bootable data) and put a raid10 array in its place. All my testing indicates that I get the same write performance but nearly double the read speed (due to interleaving I guess). It seemed to good to be true, thus I am asking the question. Could you elaborate on your last sentence? Are there downsides I could not think of? Thank you! Peter