From owner-freebsd-questions@FreeBSD.ORG Tue Jul 27 00:57:29 2010 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 547551065674 for ; Tue, 27 Jul 2010 00:57:29 +0000 (UTC) (envelope-from rl001@pacbell.net) Received: from web81101.mail.mud.yahoo.com (web81101.mail.mud.yahoo.com [68.142.199.93]) by mx1.freebsd.org (Postfix) with SMTP id 081288FC0A for ; Tue, 27 Jul 2010 00:57:28 +0000 (UTC) Received: (qmail 90181 invoked by uid 60001); 27 Jul 2010 00:57:28 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pacbell.net; s=s1024; t=1280192248; bh=d07+Vg4Pc8XCICiA+9hEEzrI5zokJ1tp00rxiPCjQ+Y=; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type; b=mKbsA+ENMqKVo8cB4C8F3wBGOzTT4nAv5+eX0GP2DZt4Sm35a0u6SdoapOnUuYib3AcACqQEeXZJQ6DhAFMp0c2AGk7mg0UhH0nJhkGzA/fj7xNxrGb8ci416bDLr2y3Hvmh7u1kYA3804kORbieTUCJucVPWGjCoRA9xZ0veXQ= DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=pacbell.net; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type; b=D166a3wXlwDWTGMbYY0tH7ls7B4oZpffwHkdTi0Q31hJs8CKR1gZFM5pq3EilHeta9vOQ3k3nr9iUQG4FEScrHXk/YHRvd7gICz8jtkHptErfi5nyArKoeN457hoZTMa9hZOyWrNnC6WZ2HH9AupDjAcHDu1DAzpGmakDafQMmM=; Message-ID: <415755.90090.qm@web81101.mail.mud.yahoo.com> X-YMail-OSG: T4iEzhMVM1nHmoMj.81W.bCwSclwv1p907yvMmrmWR1i5P1 fpW2sjaAHreYEkVpgXVCZPGQhz3sDKyq80ujAE883k6N6_jFf9P.2DUqm8dw F3L45sB8cDu4RRw2z71wkrEGDXte943frGdkJJxBF9tw.BaPmphJQuuQVeBr Rc6BTx49Aeelfc3E09pl9eujWyDzdDZmCAXLbrZmX05wA.EEqvO9N8pD9o.s _46nk61BGXw_NuStcr.AyoBMuXimoFhL1SKAbsq.EksHgcodEPUt287xlE5F 62Sbe8LI2cTh9eakvWHThvnxZ1nPENBUTkqqMykKvlKg- Received: from [71.139.201.38] by web81101.mail.mud.yahoo.com via HTTP; Mon, 26 Jul 2010 17:57:28 PDT X-Mailer: YahooMailRC/420.4 YahooMailWebService/0.8.104.276605 References: <4C4DDA28.4070205@identry.com> <980022A0-7623-40A5-BCDE-4909A721933D@mac.com> <4C4DF067.7000801@identry.com> <29133_1280176880_4C4DF2F0_29133_203_1_D9B37353831173459FDAA836D3B4349968A910AE@WADPMBXV0.waddell.com> Date: Mon, 26 Jul 2010 17:57:28 -0700 (PDT) From: Rich To: Gary Gatten In-Reply-To: <29133_1280176880_4C4DF2F0_29133_203_1_D9B37353831173459FDAA836D3B4349968A910AE@WADPMBXV0.waddell.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: "freebsd-questions@freebsd.org" Subject: Re: 1 file system, 2 drives? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 27 Jul 2010 00:57:29 -0000 ________________________________ From: Gary Gatten Cc: "freebsd-questions@freebsd.org" Sent: Mon, July 26, 2010 1:41:19 PM Subject: RE: 1 file system, 2 drives? >From my experience (YMMV), most RAID controllers will NOT redistribute the >existing data/files onto the newly added drives. So, if you have a (3) drive >RAID5 your file exists on all three drives, as does the parity data. If you add >(2) drives, your original files will not be on the new drives. New files WILL >use all (5) drives. IMHO it's best to backup the data (twice), create a new >volume on the new RAID, and restore the data. That said, maybe better/newer >RAID controllers will redistribute / balance existing data across all drives in >the array - I don't know for sure. Either way, backup your data - twice! And >make sure it can be restored! Just because the backup app SAYS it's OK, it's >NOT OK until it can be successfully restored! Also, if you go from (7) drives to (3), your I/O may suffer. Newer faster drives MAY make up the difference, or make up enough of it that it won't impact your client. Just be aware this is a potential issue. Generally speaking more spindles = more I/O's / sec. G >>Generally speaking more spindles = more I/O's / sec. and more chance for failure. After a certain point adding more drives to a RAID0 stripe doesn't buy you anything because the first one is ready for the next command before you get very far down the line. -----Original Message----- From: owner-freebsd-questions@freebsd.org [mailto:owner-freebsd-questions@freebsd.org] On Behalf Of John Almberg Sent: Monday, July 26, 2010 3:31 PM To: Chuck Swiger Cc: freebsd-questions@freebsd.org Subject: Re: 1 file system, 2 drives? > If you have hardware controller with RAID capabilities, using native RAID is >better, otherwise look towards gvinum or maybe ccd; see also: > I've just been reading up on RAID in my Absolute FreeBSD book, and it occurs to me that my client has a SCSI RAID drive chassis that he is using stupidly... It's a 14 bay drive, and he's currently got seven 32G drives stuck in it, configured with RAID-0. This is the original 200G drive I was talking about. It's a few years old. Over the next few years, this guy is going to need lots of storage for his videos. After a bit of reading, I'm wondering if the best idea might be to toss out those 32G drives and replace them with 3 big (say, 300G) drives configured with RAID-5. It sounds to me like a RAID-5 array can be expanded by adding new drives. QUESTION: is expansion normally a matter of just plugging in a new drive? Is the new drive automatically grafted onto the old drives? Or do you have to go through a process like, backing up the data, plugging in the new drive, reformatting the expanded array of drives, and restoring the data. I don't know the brand/model of the RAID drive chassis, but the client thinks it can be switched to use RAID 5. I'm waiting for the technical details, but assuming it can handle RAID-5 for now. Thanks: John _______________________________________________ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org"
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