From owner-freebsd-hackers@FreeBSD.ORG Wed Mar 17 18:12:03 2010 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 9538D106566B for ; Wed, 17 Mar 2010 18:12:03 +0000 (UTC) (envelope-from olivier@gid0.org) Received: from mail-bw0-f216.google.com (mail-bw0-f216.google.com [209.85.218.216]) by mx1.freebsd.org (Postfix) with ESMTP id 201FB8FC08 for ; Wed, 17 Mar 2010 18:12:02 +0000 (UTC) Received: by bwz8 with SMTP id 8so1338499bwz.3 for ; Wed, 17 Mar 2010 11:12:02 -0700 (PDT) MIME-Version: 1.0 Received: by 10.204.132.131 with SMTP id b3mr1409662bkt.135.1268849521091; Wed, 17 Mar 2010 11:12:01 -0700 (PDT) In-Reply-To: References: <86tysf58a2.fsf@ds4.des.no> Date: Wed, 17 Mar 2010 19:12:01 +0100 Message-ID: <367b2c981003171112n785ea9d4q21d00b533819ca67@mail.gmail.com> From: Olivier Smedts To: Thiago Damas Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: =?ISO-8859-1?Q?Dag=2DErling_Sm=F8rgrav?= , Mohacsi Janos , freebsd-hackers@freebsd.org Subject: Re: ATA 4K sector issues X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 17 Mar 2010 18:12:03 -0000 2010/3/17 Thiago Damas : > =A0I had problem with ZFS. > =A0With gnop -S 4096, it works well on /dev/ad{a}X.nop; but I decided to = not > use those disks. So maybe this was not a ZFS problem but a partition misalignment problem ? On a properly aligned partition with a physical sector size of 4KB and a logical sector size of 512 bytes, will ZFS try to use blocksizes of less than 4KB ? Blocksize in ZFS seems to be dynamic (at least when not told to use a fixed blocksize), but I didn't see somewhere in the manpage or Sun's website which minimum blocksize ZFS would use for small files, and if there is a lower limit on blocksizes to use. > > > 2010/3/17 Mohacsi Janos > >> >> >> >> On Wed, 17 Mar 2010, Dag-Erling Sm?rgrav wrote: >> >> =A0Mohacsi Janos writes: >>> >>>> What is the situation with ATA 4K dirves in FreeBSD? Are there >>>> any support for them in fdisk or disklabel? >>>> >>> >>> Hmm, didn't we discuss this already? =A0All we need to do is change the >>> defaults in fdisk so it rounds partition offsets and sizes to a multipl= e >>> of 8 sectors (or 16 for future-proofing) instead of aligning them with >>> fictitious cylinder boundaries. =A0Bsdlabel, as disklabel is properly >>> known, already DTRT: by default, the first partition starts at offset >>> 16. =A0Just make sure you specify sizes that are divisible by 8 or 16 >>> blocks (not an issue if you use the M or G suffixes). =A0Sysinstall >>> operates in megabytes. >>> >> >> Thanks for the information. >> >> >> _______________________________________________ >> freebsd-hackers@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-hackers >> To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.or= g" >> > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org= " > --=20 Olivier Smedts _ ASCII ribbon campaign ( ) e-mail: olivier@gid0.org - against HTML email & vCards X www: http://www.gid0.org - against proprietary attachments / \ "Il y a seulement 10 sortes de gens dans le monde : ceux qui comprennent le binaire, et ceux qui ne le comprennent pas."