From owner-freebsd-stable@FreeBSD.ORG Mon Oct 13 21:56:52 2014 Return-Path: Delivered-To: freebsd-stable@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 0EFFA78B; Mon, 13 Oct 2014 21:56:52 +0000 (UTC) Received: from mail-in7.apple.com (mail-out7.apple.com [17.151.62.29]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id D7B66679; Mon, 13 Oct 2014 21:56:51 +0000 (UTC) Received: from mail-out.apple.com (mail-out.apple.com [17.151.62.51]) (using TLS with cipher RC4-MD5 (128/128 bits)) (Client did not present a certificate) by mail-in7.apple.com (Apple Secure Mail Relay) with SMTP id 7C.2D.31401.3AA4C345; Mon, 13 Oct 2014 14:56:51 -0700 (PDT) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; CHARSET=US-ASCII Received: from relay5.apple.com ([17.128.113.88]) by local.mail-out.apple.com (Oracle Communications Messaging Server 7.0.5.30.0 64bit (built Oct 22 2013)) with ESMTP id <0NDE00MAKKYRJD51@local.mail-out.apple.com>; Mon, 13 Oct 2014 14:56:51 -0700 (PDT) X-AuditID: 11973e16-f793b6d000007aa9-68-543c4aa35376 Received: from [17.149.228.210] (Unknown_Domain [17.149.228.210]) (using TLS with cipher AES128-SHA (128/128 bits)) (Client did not present a certificate) by relay5.apple.com (Apple SCV relay) with SMTP id 4C.54.31858.4AA4C345; Mon, 13 Oct 2014 14:56:52 -0700 (PDT) Subject: Re: getting to 4K disk blocks in ZFS From: Charles Swiger In-reply-to: Date: Mon, 13 Oct 2014 14:56:49 -0700 Message-id: <77AA5757-5DC1-415B-899E-30545BF91516@mac.com> References: <201410132047.s9DKlGxD030176@gw.catspoiler.org> To: Lyndon Nerenberg X-Mailer: Apple Mail (2.1878.6) X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrMLMWRmVeSWpSXmKPExsUiON3OWHexl02IQUeLlMXhZiGLk03NrA5M HjM+zWcJYIzisklJzcksSy3St0vgymjumMlSMJ+tYtbcbqYGxi7WLkZODgkBE4nV99awQNhi EhfurWfrYuTiEBKYxSQxcc9BdpAEr4CgxI/J94CKODiYBeQlDp6XBQkzC2hJfH/UygJR38Qk 0fN4AhPM0Aub+xghEv1MEhv3rQJLCAvoSjy7/YcRZBCbgJrEhIk8IGFOATuJCSs+ge1iEVCV +DP5GgvEAgeJjpnbWUHKeQWsJC79MQAJCwnkS/xp+gM2UURAQ2L69X9Qa+UlPnw4zg6yVkLg N6vE1YVv2ScwCs9C8sIshBdmIXlhASPzKkah3MTMHN3MPHO9xIKCnFS95PzcTYyQUBbbwfhw ldUhRgEORiUe3k4n6xAh1sSy4srcQ4zSHCxK4rwflGxChATSE0tSs1NTC1KL4otKc1KLDzEy cXBKNTC6vniWN03Es/pE1+npORalbaInRKxTc0S9wwNa33pc3LJwisvW9e58N9ebmcjOzGJ6 t63uVrEew3WWyF0y/3g9xO/w8Hmd1zL+6q5idqWLI9jJ5c7V9x+YdV48XdFXzcPhnRa+wHXH G8fsCZYGOfvFjtbt0Z/PXh70X/D3HU3pHR9/3Did5qPEUpyRaKjFXFScCAAGd4oiRgIAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrGLMWRmVeSWpSXmKPExsUiOPXJJd0lXjYhBh9e8Focbhay2DL7CIvF yaZmVgdmjxmf5rN43H31mSmAKYrLJiU1J7MstUjfLoEro+9PL0vBNraKKef72BsYp7B2MXJy SAiYSFzY3McIYYtJXLi3nq2LkYtDSKCfSWLW8hY2kASzgJbEjX8vmUBsXgEDiSW7NjGD2MIC uhLPbv8BaubgYBNQk5gwkQckzClgJ7H8RSvYfBYBVYk/k6+xQIxxkuhZeARqpLbEsoWvmSFG Wkk8/tTODmILCeRKTJ14GSwuIqAhMf36PyaI2+QlPnw4zj6BkX8WkotmIbloFpKxCxiZVzEK FKXmJFaa6iUWFOSk6iXn525iBIVeQ2HEDsb/y6wOMQpwMCrx8Fr8sQoRYk0sK67MPcQowcGs JMJbyWUTIsSbklhZlVqUH19UmpNafIhRmoNFSZx3owJQSiA9sSQ1OzW1ILUIJsvEwSnVwCjG ovl7//xd0x7NOpayy5DFqtGHK3TD7c2NiW8ORP7l/f3p+zeWb8l/o65PlzrwU8jpp7CQVbKI Cv8bMwf+esfgiqhHavdtqwSzsibfKFrxSeD4krN/N0SlN+/huMppwbT0+NQGe860s5PXHFGp vTfjjxDTVrG8L1zSzhe3l24NSv2cHS30y1uJpTgj0VCLuag4EQDoI0ejOQIAAA== Cc: Don Lewis , freebsd-stable@FreeBSD.org X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 Oct 2014 21:56:52 -0000 Hi-- On Oct 13, 2014, at 2:25 PM, Lyndon Nerenberg wrote: [ ... ] > On any real-world system where you're running ZFS, it's unlikely the 4K block overhead is really going to be an issue. And the underlying disk hardware is moving to 4K physical sectors, anyway. Sooner or later you're just going to have to suck it up. Or SSDs, which currently have anywhere from 2KB to 16KB "sectors". I suspect that MIX -- http://en.wikipedia.org/wiki/MIX_%28Email%29 -- will gain in popularity. Big messages are kept one per file, just as Maildir does, but MIX also does a pretty good job of conserving inodes (or equivalent) and minimizing wasted space from intrinsic fragmentation due to filesystem blocksize by aggregating small messages together. Regards, -- -Chuck