From owner-freebsd-stable@FreeBSD.ORG Mon Oct 13 23:17:07 2014 Return-Path: Delivered-To: freebsd-stable@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 5FC79274; Mon, 13 Oct 2014 23:17:07 +0000 (UTC) Received: from smtp1.multiplay.co.uk (smtp1.multiplay.co.uk [85.236.96.35]) by mx1.freebsd.org (Postfix) with ESMTP id 24903E44; Mon, 13 Oct 2014 23:17:06 +0000 (UTC) Received: by smtp1.multiplay.co.uk (Postfix, from userid 65534) id E8A1C20E70905; Mon, 13 Oct 2014 23:17:04 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.multiplay.co.uk X-Spam-Level: ** X-Spam-Status: No, score=2.2 required=8.0 tests=AWL,BAYES_00,DOS_OE_TO_MX, FSL_HELO_NON_FQDN_1,RDNS_DYNAMIC,STOX_REPLY_TYPE autolearn=no version=3.3.1 Received: from r2d2 (82-69-141-170.dsl.in-addr.zen.co.uk [82.69.141.170]) by smtp1.multiplay.co.uk (Postfix) with ESMTPS id 1231E20E70903; Mon, 13 Oct 2014 23:17:03 +0000 (UTC) Message-ID: <49F465E3114F4244955B87BC7E90D093@multiplay.co.uk> From: "Steven Hartland" To: "Don Lewis" , References: <201410132302.s9DN2F91030438@gw.catspoiler.org> Subject: Re: getting to 4K disk blocks in ZFS Date: Tue, 14 Oct 2014 00:17:00 +0100 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 Cc: lyndon@orthanc.ca, 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 23:17:07 -0000 ----- Original Message ----- From: "Don Lewis" > On 13 Oct, Charles Swiger wrote: >> 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". > > Which is even worse because you're more likely to care about wasted > space because of the much higher cost per byte. > >> 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. > > Interesting, but it would be nice to have a more generic solution that > could be used to solve the equivalent problem with /usr/ports and > similar sorts of things. For instance, it looks like /usr/src expands > by quite a bit on an ashift=12 raidz1, though not quite as much as my > mail spool. Dont worry about ports just create a volume set it to lz4 and forget about it. Regards Steve