From owner-freebsd-fs@FreeBSD.ORG Tue Jan 3 23:31:02 2012 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 61F021065678 for ; Tue, 3 Jan 2012 23:31:02 +0000 (UTC) (envelope-from kraduk@gmail.com) Received: from mail-gy0-f182.google.com (mail-gy0-f182.google.com [209.85.160.182]) by mx1.freebsd.org (Postfix) with ESMTP id 17E7E8FC0A for ; Tue, 3 Jan 2012 23:31:01 +0000 (UTC) Received: by ghrr16 with SMTP id r16so7002058ghr.13 for ; Tue, 03 Jan 2012 15:31:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=xZfxlMq4UZcQsZBW2TTjilFoRrgZJXjLZ9PGDiNpOQk=; b=kGq81gz1gwQbpU7BUU1IR4PSq1YGSJ0BBBszB7P+SGkVzGjZvmshgVKaC1HuO23tQb FisRRBvBOadaEntZzLlUO2RrJT3UD9sXY92pBSMeGMcD/paYWJQsmLQUZ7H4aVkAl6Df XOlZCMFQhW+YTreH2iXylTie5PAWlGnbbJzTk= MIME-Version: 1.0 Received: by 10.236.150.134 with SMTP id z6mr70419330yhj.42.1325633461393; Tue, 03 Jan 2012 15:31:01 -0800 (PST) Received: by 10.236.139.193 with HTTP; Tue, 3 Jan 2012 15:31:01 -0800 (PST) Received: by 10.236.139.193 with HTTP; Tue, 3 Jan 2012 15:31:01 -0800 (PST) In-Reply-To: <20120103162428.GA18661@icarus.home.lan> References: <4F003EB8.6080006@dannysplace.net> <4F02FC42.1040103@dannysplace.net> <4F0311F2.7050209@brockmann-consult.de> <4F0312DF.8050004@brockmann-consult.de> <20120103162428.GA18661@icarus.home.lan> Date: Tue, 3 Jan 2012 23:31:01 +0000 Message-ID: From: krad To: Jeremy Chadwick Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-fs@freebsd.org Subject: Re: ZFS With Gpart partitions X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 03 Jan 2012 23:31:02 -0000 There has been.quite a bit of discussion on this already and I think the safest way is to always 4k align as this works fine on.both drive types On Jan 3, 2012 4:29 PM, "Jeremy Chadwick" wrote: > > On Tue, Jan 03, 2012 at 03:38:23PM +0100, Peter Maloney wrote: > > On 01/03/2012 03:34 PM, Peter Maloney wrote: > > > On 01/03/2012 02:01 PM, Dan Carroll wrote: > > >> On 3/01/2012 10:27 PM, krad wrote: > > >>> Just a not you dont appear to be 4k aligned on this drive. As the > > >>> drive capacity is > 1.5 Tb you probably should be. You will also be > > >>> ashift=9 as well. This may or may not be a problem for you. > > >> That was intentional, as I *thought* these drives were not 4k sector > > >> drives. I am not sure how I am supposed to tell. They are WD RE4 > > >> drives. > > >> I confess, however to knowing nothing about ashift=9..... Could you > > >> elaborate? > > > Read this thread: > > > > > > ZFS using 'advanced format drives' with FreeBSD (8.2-RC3) > > > http://forums.freebsd.org/showthread.php?t=21644 > > > > > > (and of course don't play around and run the dd command, etc. for disks > > > with valuable data on them) > > > > > And looking at dmesg or /var/log/messages should probably tell you what > > your sector size is. > > > > eg. > > # dmesg | grep "da2:" > > > > or > > > > # grep "da2:" /var/log/messages > > > > or > > > > # bunzip2 -c /var/log/messages.1.bz2 | grep "da2:" > > Nov 28 13:59:35 bcnas1 kernel: da2: Fixed Direct > > Access SCSI-6 device > > Nov 28 13:59:35 bcnas1 kernel: da2: 600.000MB/s transfers > > Nov 28 13:59:35 bcnas1 kernel: da2: Command Queueing enabled > > Nov 28 13:59:35 bcnas1 kernel: da2: 2861588MB (5860533168 *512 byte > > sectors*: 255H 63S/T 364801C) > > This is incorrect. Most 4KB sector drives advertise a logical sector > size of 512 (this is to maintain/guarantee full compatibility with older > OSes and existing software), while sometimes advertising a physical > sector size of 4096. Comparatively, Intel SSDs advertise both a logical > and physical sector size of 512, even though we all know better. > > Use either "camcontrol identify" or "camcontrol inquiry" (which command > depends on if you're using SATA-via-CAM or native SCSI) to find out. If > this doesn't work for you, try using smartmontools (if there's a > difference between logical/physical it will display both, otherwise > it'll say "logical/physical" literally). > > -- > | Jeremy Chadwick jdc at parodius.com | > | Parodius Networking http://www.parodius.com/ | > | UNIX Systems Administrator Mountain View, CA, US | > | Making life hard for others since 1977. PGP 4BD6C0CB | > > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" There has been.quite a bit of discussion on this already and I think the safest way is to always 4k align as this works fine on.both drive types