From owner-freebsd-current@FreeBSD.ORG Mon Dec 19 20:40:35 2011 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3589D106566C for ; Mon, 19 Dec 2011 20:40:35 +0000 (UTC) (envelope-from peter.maloney@brockmann-consult.de) Received: from mo-p05-ob6.rzone.de (mo-p05-ob6.rzone.de [IPv6:2a01:238:20a:202:53f5::1]) by mx1.freebsd.org (Postfix) with ESMTP id 9C7B08FC0C for ; Mon, 19 Dec 2011 20:40:34 +0000 (UTC) X-RZG-AUTH: :LWIKdA2leu0bPbLmhzXgqn0MTG6qiKEwQRWfNxSw4HzYIwjsnvdDt2QV8d370WOpHNjtl+s= X-RZG-CLASS-ID: mo05 Received: from [192.168.179.42] (hmbg-4d06f6f1.pool.mediaWays.net [77.6.246.241]) by smtp.strato.de (cohen mo51) (RZmta 26.15 DYNA|AUTH) with (DHE-RSA-AES256-SHA encrypted) ESMTPA id a03c31nBJJcI94 ; Mon, 19 Dec 2011 21:40:14 +0100 (MET) Message-ID: <4EEFA12D.2070803@brockmann-consult.de> Date: Mon, 19 Dec 2011 21:40:13 +0100 From: Peter Maloney User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:8.0) Gecko/20111105 Thunderbird/8.0 MIME-Version: 1.0 To: Michael Reifenberger References: <4EEF488E.1030904@freebsd.org> <4EEF5B5C.90905@brockmann-consult.de> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-current@freebsd.org Subject: Re: Uneven load on drives in ZFS RAIDZ1 X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 19 Dec 2011 20:40:35 -0000 Am 19.12.2011 17:48, schrieb Michael Reifenberger: > On Mon, 19 Dec 2011, Peter Maloney wrote: > >> Swapping disks (or even removing one depending on controller, etc. when >> it fails) without labels can be bad. >> eg. > > Since ZFS uses (and searches for) its own UUID partition signatures s > disk wapping shouldn't matter as long enough disks are found. > > Set vfs.zfs.debug=1 during boot to watch what is searched for. > > Bye/2 > --- > Michael Reifenberger > Michael@Reifenberger.com > http://www.Reifenberger.com > Thanks for the info. But I am confused by it, because when my disks moved around randomly on reboot, it really did mess things up. The first few times it happened, there was no issue, but when a spare took the place of a pool disk, it messed things up. I can see the UUIDs when I look at zdb output, so I really have no idea why it messed things up. ... but it did, so I will always caution people anyway. I can't point you to any relevant lines of code that cause the problem, but I know it can happen... and it will when you least expect it. ;) And I also see the opposite... people talking about their very old pools, with many disks exchanged, and wonder why mine was so easily messed up and theirs survived so long without labels. I just assumed it was the way the controller arranged the disks. (and by the way, mine now orders the disks perfectly consistently now that it is in IT mode, not mostly random like before... could be a factor) I am always very busy, but when I get the chance, it shouldn't take too long, so I will try to recreate it on a virtual machine and try vfs.zfs.debug=1.Thanks for the suggestion.