From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C9F4C433B4 for ; Mon, 17 May 2021 20:53:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5A635611BF for ; Mon, 17 May 2021 20:53:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234405AbhEQUzG (ORCPT ); Mon, 17 May 2021 16:55:06 -0400 Received: from vps.thesusis.net ([34.202.238.73]:33664 "EHLO vps.thesusis.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233271AbhEQUzG (ORCPT ); Mon, 17 May 2021 16:55:06 -0400 Received: from localhost (localhost [127.0.0.1]) by vps.thesusis.net (Postfix) with ESMTP id 386542154A; Mon, 17 May 2021 16:53:49 -0400 (EDT) Received: from vps.thesusis.net ([127.0.0.1]) by localhost (vps.thesusis.net [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id NB9SPu4DprFO; Mon, 17 May 2021 16:53:48 -0400 (EDT) Received: by vps.thesusis.net (Postfix, from userid 1000) id EC21F21548; Mon, 17 May 2021 16:53:48 -0400 (EDT) References: <2140221131.2872520.1620837067395.JavaMail.zimbra@karlsbakk.net> <87a6oyr64b.fsf@vps.thesusis.net> <3f3fd663-77e4-8c23-eb22-1b8223eaf277@turmel.org> <87y2ch4c3w.fsf@vps.thesusis.net> <947223877.4161967.1621003717636.JavaMail.zimbra@karlsbakk.net> User-agent: mu4e 1.5.7; emacs 26.3 From: Phillip Susi To: Roy Sigurd Karlsbakk Cc: Phil Turmel , d tbsky , Linux Raid Subject: Re: raid10 redundancy Date: Mon, 17 May 2021 16:50:12 -0400 In-reply-to: <947223877.4161967.1621003717636.JavaMail.zimbra@karlsbakk.net> Message-ID: <87cztpm68z.fsf@vps.thesusis.net> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org Roy Sigurd Karlsbakk writes: > RAID10 is like RAID1+0, only a bit more fancy. That means it's > basically striping across mirrors. It's *not* like RAID0+1, which is > the other way, when you mirror two RAID0 sets. So when a drive dies in > a RAID10, you'll have to read from one or two other drives, depending > on redundancy and the number of drives (odd or even). Yes... what does that have to do with what I said? My point was that as long as you are IO bound, it doesn't make much difference between having to read all of the disks in the stripe for a raid6 and having to read some number that is possibly less than that for a raid10. They both take about the same amount of time as just writing the data to the new disk.