From owner-freebsd-stable@FreeBSD.ORG Wed Nov 19 18:51:33 2014 Return-Path: <owner-freebsd-stable@FreeBSD.ORG> 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 46038B3B for <freebsd-stable@freebsd.org>; Wed, 19 Nov 2014 18:51:33 +0000 (UTC) Received: from mail-qa0-f50.google.com (mail-qa0-f50.google.com [209.85.216.50]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 05B93E7 for <freebsd-stable@freebsd.org>; Wed, 19 Nov 2014 18:51:32 +0000 (UTC) Received: by mail-qa0-f50.google.com with SMTP id w8so820904qac.37 for <freebsd-stable@freebsd.org>; Wed, 19 Nov 2014 10:51:26 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=mFDpeeROwVSayrUCvf9yRELenu7i8eKJmiWGe7e6sik=; b=ezXbmtkUUvzvvtYtlBnY59/GrbDe7yjP+IhMvCMag7reP5v31t3gDkp+r4O5qTaGFS DzIP0qLP9HR+Mr4woX/NjN1XhRswEgynsWo/4D3nUgx88XQ6j3UoODvmwvTvGdN3CXf9 EvWBEjD2FPTGsFv6LeZcWtGP7CICwSqrKo5ucKMGFCBlw5ZIpv0+Obwk8bKLseL+zpfc 83/7RamzPVClVfX19RgAi8Ii6t3raMEiPHnVZscXAHjKIDaAEJzQ/m4AXC5fSGrdhgyZ b+4VW2FdXDdQysGZRzlD/l7ykB7ewZlrdLTdMY0ebSBtfqdiPYzmrOONC2qNr5ksn5Dm SdLA== X-Gm-Message-State: ALoCoQlAoG3WtKxWuIPkdMbhPZcKHwv2CTKNVcbz798Z5tydy6HnHPc4JUsEg0Xva0CwgEmwgNa3 MIME-Version: 1.0 X-Received: by 10.224.167.132 with SMTP id q4mr52874214qay.48.1416422662339; Wed, 19 Nov 2014 10:44:22 -0800 (PST) Received: by 10.229.14.4 with HTTP; Wed, 19 Nov 2014 10:44:22 -0800 (PST) In-Reply-To: <ead753e90b2b74b169af2fb04c525c9e@mailbox.ijs.si> References: <A2328132-EC43-4E27-8D01-A4D774634598@punkt.de> <ead753e90b2b74b169af2fb04c525c9e@mailbox.ijs.si> Date: Wed, 19 Nov 2014 12:44:22 -0600 Message-ID: <CADNPKbPC7h7Q0WRQM7sFSPUPMNjAJ7ERkzUS7zkxNJJBPa-wjg@mail.gmail.com> Subject: Re: 10.1 fresh install and 4k alignment From: Aidan Scheller <aidan@aodhandigital.com> To: Mark Martinec <Mark.Martinec+freebsd@ijs.si> Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.18-1 Cc: 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 <freebsd-stable.freebsd.org> List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-stable>, <mailto:freebsd-stable-request@freebsd.org?subject=unsubscribe> List-Archive: <http://lists.freebsd.org/pipermail/freebsd-stable/> List-Post: <mailto:freebsd-stable@freebsd.org> List-Help: <mailto:freebsd-stable-request@freebsd.org?subject=help> List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>, <mailto:freebsd-stable-request@freebsd.org?subject=subscribe> X-List-Received-Date: Wed, 19 Nov 2014 18:51:33 -0000 Hi Mark, Did you submit a PR for this? I'm not able to find anything related in Bugzilla and am wondering we should do so. Thanks, Aidan On Wed, Nov 19, 2014 at 8:32 AM, Mark Martinec <Mark.Martinec+freebsd@ijs.si > wrote: > Patrick M. Hausen wrote: > >> Hi, all, >> >> I just installed a new machine with 10.1-RELEASE using the memstick >> installer >> and chosing ZFS mirror root as the disk layout. >> >> I did check the "4k" option, watched the installer do the necessary gnop >> dance >> and the pool seems to be OK: >> >> root@seleniumhub:~ # zdb | grep ashift >> ashift: 12 >> >> But this puzzles me a bit: >> >> root@seleniumhub:~ # gpart list ada0 >> Mediasize: 524288 (512K) >> Sectorsize: 512 >> ... >> Providers: >> 1. Name: ada0p1 >> Mediasize: 524288 (512K) >> Sectorsize: 512 >> ... >> end: 1057 >> start: 34 >> ... >> 3. Name: ada0p3 >> Mediasize: 465747565056 (434G) >> Sectorsize: 512 >> ... >> type: freebsd-zfs >> ... >> end: 976773134 >> start: 67109922 >> >> None of the start sector numbers is a multiple of 8, neither are the end >> sectors >> a multiple of 8 minus 1. >> >> So the pool uses a 4k block size but it starts on an odd multiple of >> 2k on the platter >> - do I see this correctly? >> >> Isn't it absolutely necessary that the simulated 4k blocks are laid >> out so that the first >> is made from 512 byte sectors 0-7, the second from 8-15 and so on? >> >> Then why does the installer start the first partition at 512 byte >> sector 34? While I'm at >> it, this magic number is everywhere in the older documentation, e.g. >> for manually >> installing FreeBSD 8 with gptzfsboot - where does that 34 come from? It's >> not >> a power of 2 nor is it one of the historical CHS magic numbers that would >> mean >> a cylinder boundary or similar. Size of the GPT partition table itself? >> >> Is this a bug in the installer? Will I still have to layout the disks >> manually if I want 4k >> alignment? What's a good offset for the first partition in this case? >> Anything bigger >> than 34 that's a multiple of 8 - 40 or 64? >> >> Thanks in advance >> Patrick >> > > > Reported on 2014-10-10, but was apparently forgotten/ignored: > > "GPT partitions not 4k aligned by 10.1-RC1 installer" > https://lists.freebsd.org/pipermail/freebsd-stable/2014- > October/080509.html > > > Mark > > > > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org" >