From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id B9F531381F3 for ; Sun, 15 Sep 2013 11:15:17 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 3A908E0D48; Sun, 15 Sep 2013 11:15:08 +0000 (UTC) Received: from mail-qe0-f47.google.com (mail-qe0-f47.google.com [209.85.128.47]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 37020E0D0F for ; Sun, 15 Sep 2013 11:15:06 +0000 (UTC) Received: by mail-qe0-f47.google.com with SMTP id b4so2135828qen.6 for ; Sun, 15 Sep 2013 04:15:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=tOeOVqCNzAlBxGOvnZs81r3MstjskcUvVPAiwAZLpqg=; b=KViC6u7hyhK4iRnZ/FsGm/ocD9eLFq9+NrnoSndqJ9B766D9MUcUAiv34WHrJWa9su HX93g1K6Hyp5OLlQlveUYLN43V541wYCX6ir3RxaRAxB9Fxra+YmowrCvfAlzRNFpyUO S2p1+/zmxa724Eeo9e/IgzuGV67AldHGf1h3iAI32sNF2c8yLs2c9pBZUTpH6riM+unb omWheCspqs0FfzMjxHoDD6DHIKFZHm3pZ2acFDYfE9NGLJsXdI4hTwSEavR6gwMmnSkN 3eiGcxiu/M3zu3McPG9FRdeIwusB0nkCOWu+2/x2ihGnfN7rPn/hFqrq+3TLz3HBAH0x MDZA== Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 X-Received: by 10.49.121.134 with SMTP id lk6mr40434483qeb.23.1379243706391; Sun, 15 Sep 2013 04:15:06 -0700 (PDT) Received: by 10.140.25.83 with HTTP; Sun, 15 Sep 2013 04:15:06 -0700 (PDT) In-Reply-To: <5234494B.9010301@libertytrek.org> References: <5233792D.7040900@orlitzky.com> <3910524.4C314ckqDu@wstn> <52339798.5000409@gmail.com> <5234494B.9010301@libertytrek.org> Date: Sun, 15 Sep 2013 04:15:06 -0700 Message-ID: Subject: Re: [gentoo-user] {OT} Need a new server From: Grant To: Tanstaafl Cc: Gentoo mailing list Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable X-Archives-Salt: 88251262-ed38-421d-8252-3aa20eb9f507 X-Archives-Hash: ffdf225d744b86f5432556454c6e1b06 >> http://blog.open-e.com/why-a-hot-spare-hard-disk-is-a-bad-idea/ >> >> "Based on our long years of experience we have learned that during a >> RAID rebuild the probability of an additional drive failure is quite >> high =96 a rebuild is stressful on the existing drives." > > This is NOT true on a RAID 10... a rebuild is only stressful on the other > drive in the mirrored pair, not the other drives. > > But, it is true for that one drive. Why wouldn't it be true of RAID 10? Each drive only has one mirror, so if a drive fails, its only mirror will be stressed by the rebuild won't it? > That said, it would be nice is the auto rebuild could be scripted such th= at > a backup could be triggered and the auto-rebuild queued until the backup = was > complete. > > But, here is the problem there... a backup will stress the drive almost a= s > much as the rebuild, because all the rebuild does is read/copy the conten= ts > of the one drive to the other one (ie, it re-mirrors). > >> Instead, how about a 6-drive RAID 10 array with no hot spare? My >> guess is this would mean much greater fault-tolerance both overall and >> during the rebuild process (once a new drive is swapped in). That >> would mean not only potentially increased uptime but decreased >> monitoring responsibility. > > I would still prefer a hot spare to not... in the real world, it has save= d > me exactly 3 out of 3 times... You would prefer 4-drive RAID 10 plus a hot spare to 6-drive RAID 10? Isn't 6-drive RAID 10 superior in every way except for cost (1 extra drive)? - Grant