From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1RVTMi-0001Qc-Jc for garchives@archives.gentoo.org; Tue, 29 Nov 2011 19:29:16 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id C0BA621C18A; Tue, 29 Nov 2011 19:29:01 +0000 (UTC) Received: from mail-bw0-f53.google.com (mail-bw0-f53.google.com [209.85.214.53]) by pigeon.gentoo.org (Postfix) with ESMTP id 45DA321C16E for ; Tue, 29 Nov 2011 19:27:33 +0000 (UTC) Received: by bkaq10 with SMTP id q10so12378131bka.40 for ; Tue, 29 Nov 2011 11:27:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; bh=gfteKdBgTryyz+fMbA0a9r+j3kd9eJKVXw64yYqkuPU=; b=o2dey3feYZppnrXq3W6jtsAUqXacApGOectwodN/BfHIcTHyeurpgMv4TyaqCr16S3 YmsOE/qnO40O/Cm5uxciV2BalIIRexGTHhAeDzGw0bRXTN13ecdrUFrIJZQtac+NSNb8 lMONP25xrTp2AZsTS7kV12bZA9GoWCff+x8nQ= 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 Received: by 10.204.154.25 with SMTP id m25mr50964696bkw.140.1322594852337; Tue, 29 Nov 2011 11:27:32 -0800 (PST) Received: by 10.204.14.7 with HTTP; Tue, 29 Nov 2011 11:27:32 -0800 (PST) In-Reply-To: <4ED53120.2030209@binarywings.net> References: <4ED484B5.4030700@binarywings.net> <4ED52277.4060304@binarywings.net> <4ED53120.2030209@binarywings.net> Date: Tue, 29 Nov 2011 14:27:32 -0500 Message-ID: Subject: Re: [gentoo-user] dmraid, mdraid, lvm, btrfs, what? From: Michael Mol To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Archives-Salt: 26664ab8-accd-4924-a225-6071272e772f X-Archives-Hash: c38aa7d204d59dd355aee2201ef0df4d On Tue, Nov 29, 2011 at 2:23 PM, Florian Philipp wr= ote: > Am 29.11.2011 19:39, schrieb Michael Mol: >> On Tue, Nov 29, 2011 at 1:20 PM, Florian Philipp = wrote: >>> Am 29.11.2011 14:44, schrieb Michael Mol: >>>> On Tue, Nov 29, 2011 at 2:07 AM, Florian Philipp wrote: >>>>> Am 29.11.2011 05:10, schrieb Michael Mol: >>>>>> I've got four 750GB drives in addition to the installed system drive= . >>>>>> >>>>>> I'd like to aggregate them and split them into a few volumes. My fir= st >>>>>> inclination would be to raid them and drop lvm on top. =C2=A0I know = lvm well >>>>>> enough, but I don't remember md that well. >>>>>> >>>>>> Since I don't recall md well, and this isn't urgent, I figure I can = look >>>>>> at the options. >>>>>> > [...] >>>>> What kind of RAID level do you want to use, 10 or 5? You >>>>> can also split it: Use a smaller RAID 10 for performance-critical >>>>> partitions like /usr and the more space-efficient RAID 5 for bulk lik= e >>>>> videos. You can handle this with one LVM volume group consisting of t= wo >>>>> physical volumes. Then you can decide on a per-logical-volume basis >>>>> where it should allocate space and also migrate LVs between the two P= Vs. >>>> >>>> Since I've got four disks for the pool, I was thinking raid10 with lvm >>>> on top, and a single lvm pv above that. >>>> >>> >>> Yeah, that would also be my recommendation. But if storage efficiency i= s >>> more relevant, RAID-5 with 4 disks brings you 750GB more usable storage= . >>> >>> >> >> It looks like I'll want to try two different configurations. RAID5 and >> RAID10. Not for different storage requirements, but I want to see >> exactly what the performance drop is. >> >> I wish lvm striping supported data redundancy. But, then, I wish btrfs >> was ready... >> > > Just out of curiosity: What happens if you do `lvcreate --mirrors 1 > --stripes 2 ...`? Does it create something similar to a RAID-10 or does > it simply fail? Hm. I don't know. Honestly, I didn't know about that functionality. Perhaps it's time I catch up on the docs again. --=20 :wq