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 8C2391381F3 for ; Fri, 20 Sep 2013 22:44:14 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 79DABE0B7A; Fri, 20 Sep 2013 22:44:06 +0000 (UTC) Received: from mail-pa0-f44.google.com (mail-pa0-f44.google.com [209.85.220.44]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 46CA9E09E4 for ; Fri, 20 Sep 2013 22:44:04 +0000 (UTC) Received: by mail-pa0-f44.google.com with SMTP id fz6so1252893pac.31 for ; Fri, 20 Sep 2013 15:44:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:content-type; bh=NOb730+inEeKeoGx8LYanbqIuEq4oLlNH8NzDLa+Pwg=; b=uRGKJrTt3pewnW5HJlGLmKFiarxiTPT8npNCu7GTsjEuVcAKtZGwDXkPVJOKOAmARJ pDvARZDweoujykjiR/hceiFaR8+S6KIkszftvehBbFf48Mug+L69xsiOzxlpwIiQOdL1 hBUibx7SjA/Z/T+PhdzyxFklY1JLqb/mvMrT4X6UCmXZEVHQccx0pfPx53PbetsO7nMG nddY7kPOd8o33YA5HUsKacLfN3P+HrNL8m9UbNMl36ifbVVqF55XwZITu/NPBfDPvdVL DyNDKJ8aTIMtkk2kyklyr2Vj8a3kfQq/OT3NRaOgWjFc5F66RK1xoEBmU7MxBgxINslq ImQA== X-Received: by 10.66.158.72 with SMTP id ws8mr11320284pab.39.1379717044064; Fri, 20 Sep 2013 15:44:04 -0700 (PDT) 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 Sender: paul.hartman@gmail.com Received: by 10.70.37.3 with HTTP; Fri, 20 Sep 2013 15:43:43 -0700 (PDT) In-Reply-To: <523C2F89.6050401@libertytrek.org> References: <523C2F89.6050401@libertytrek.org> From: Paul Hartman Date: Fri, 20 Sep 2013 17:43:43 -0500 X-Google-Sender-Auth: XemEBeMTmU3L755nIRdSHS8l7Zw Message-ID: Subject: Re: [gentoo-user] Comparing RAID5/6 rebuild times, SATA vs SAS vs SSD To: Gentoo User Content-Type: text/plain; charset=ISO-8859-1 X-Archives-Salt: 60d571c4-40b3-4607-9633-b988d465bb6b X-Archives-Hash: 05e99c77161e639202730f9e64a221dc On Fri, Sep 20, 2013 at 6:20 AM, Tanstaafl wrote: > Hi all, > > Being that one of the big reasons I stopped using RAID5/6 was the rebuild > times - can be DAYS for a large array - I am very curious if anyone has > done, or knows of anyone who has done any tests comparing rebuild times when > using slow SATA, faster SAS and fastest SSD drives. > > Of course, this question is moot if using ZFS RAID, but not every situation > or circumstance will allow it... I don't have an all-out comparison, but at least a data point for you with somewhat cheap and recent hardware. I have a new (2 months old) home RAID6 made out of: 6 Western Digital Red 3TB SATA drives LSI 9200-8e SAS JBOD controller Sans Digital TR8X+B SAS/SATA enclosure w/ SFF-8088 cables I created a standard linux software RAID6 using mdadm, resulting in 11TB of usable space (4 data drives, 2 parity). A couple weeks ago one of the drives died. I hot-swap replaced it with a new one (with no down-time) and the rebuild took exactly 10 hours. Under normal operation, the speed of the array for contiguous read/writes is about 600MB/sec, which is faster than my SSD (single drive, not RAIDed). FWIW