From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id 35250139083 for ; Thu, 7 Dec 2017 07:55:32 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id AEFB7E0EE1; Thu, 7 Dec 2017 07:55:25 +0000 (UTC) Received: from out5-smtp.messagingengine.com (out5-smtp.messagingengine.com [66.111.4.29]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 49191E0EC7 for ; Thu, 7 Dec 2017 07:55:25 +0000 (UTC) Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id 7407221C4E for ; Thu, 7 Dec 2017 02:55:24 -0500 (EST) Received: from frontend2 ([10.202.2.161]) by compute6.internal (MEProxy); Thu, 07 Dec 2017 02:55:24 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; bh=EFY1va qQ/z7IO4LBB1q8DILIOlC9rwF2EFC+ZYAeLUI=; b=KsuwyjSRfqTyPwGvwdN7qX TJx6wTtHzo1/cOPoLhxYI5K+VVzTyoiXMRFstRM+eNtlkt0XUgZViKz9Suvwv/Zv 94JM0/mj0TCQ0MPNjafhQAQDAIrJJ4owtK5g6hcyd+ir5FzkydIMZGExzXHu5nvH xgXUNAUtXdv4ruCT4Ur2tPK+Hs2y2T6fCqvp7re4uc0wC2l0elpVjKB3I5XqomCQ sZX5ohO2b6i50BNcrzc+BCTl+Xgx5Ej30/heC7rXJntXL+6Rccp4+oOLkqBnwCeO pogMuz/V335H/SLL3bPny1YfAgM9UzsCsbyjYlh9M/qIpRhsD43RynLSBeGPykkw == X-ME-Sender: Received: from localhost (unknown [185.24.122.218]) by mail.messagingengine.com (Postfix) with ESMTPA id 0D79724E77 for ; Thu, 7 Dec 2017 02:55:23 -0500 (EST) Date: Thu, 7 Dec 2017 07:54:41 +0000 From: Richard Bradfield To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] OT: btrfs raid 5/6 Message-ID: <20171207075441.rwzd5qlk7mdm7rtn@carbon> Mail-Followup-To: gentoo-user@lists.gentoo.org References: <5A218A49.3050004@youngman.org.uk> <20171206232829.GA5249@tp> 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 Content-Type: text/plain; charset=utf-8; format=flowed Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: NeoMutt/20171027 X-Archives-Salt: 43a586f2-807a-4867-b6dc-08f078ba72b7 X-Archives-Hash: 85a87b6c0f5105d4b1e28f86ea50cc3e On Wed, Dec 06, 2017 at 06:35:10PM -0500, Rich Freeman wrote: >On Wed, Dec 6, 2017 at 6:28 PM, Frank Steinmetzger wrote: >> >> I don’t really care about performance. It’s a simple media archive powered >> by the cheapest Haswell Celeron I could get (with 16 Gigs of ECC RAM though >> ^^). Sorry if I more or less stole the thread, but this is almost the same >> topic. I could use a nudge in either direction. My workplace’s storage >> comprises many 2× mirrors, but I am not a company and I am capped at four >> bays. >> >> So, Do you have any input for me before I fetch the dice? >> > >IMO the cost savings for parity RAID trumps everything unless money >just isn't a factor. > >Now, with ZFS it is frustrating because arrays are relatively >inflexible when it comes to expansion, though that applies to all >types of arrays. That is one major advantage of btrfs (and mdadm) over >zfs. I hear they're working on that, but in general there are a lot >of things in zfs that are more static compared to btrfs. > >-- >Rich > When planning for ZFS pools, at least for home use, it's worth thinking about your usage pattern, and if you'll need to expand the pool before the lifetime of the drives rolls around. I incorporated ZFS' expansion inflexibility into my planned maintenance/servicing budget. I started out with 4x 2TB disks, limited to those 4 bays as you are, but planned to replace those drives after a period of 3-4 years. By the time the first of my drives began to show SMART errors, the price of a 3TB drive had dropped to what I had paid for the 2TB models, so I bought another set and did a rolling upgrade, bringing the pool up to 6TB. I expect I'll do the same thing late next year, I wonder if 4TB will be the sweet spot, or if I might be able to get something larger. -- Richard