From owner-freebsd-current@FreeBSD.ORG Tue Apr 20 13:24:56 2010 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 5A6F21065673; Tue, 20 Apr 2010 13:24:56 +0000 (UTC) (envelope-from jasonjwwilliams@gmail.com) Received: from mail-iw0-f171.google.com (mail-iw0-f171.google.com [209.85.223.171]) by mx1.freebsd.org (Postfix) with ESMTP id 142B28FC0A; Tue, 20 Apr 2010 13:24:55 +0000 (UTC) Received: by iwn1 with SMTP id 1so4219404iwn.27 for ; Tue, 20 Apr 2010 06:24:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:received:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=yOWa/gdjbw4aecyJw4yGLLjtDV2g2c/duVXdZ1GE5hI=; b=XagBay5Uo56XGijjpqgPyyuVN/YH4+CSX5AYeBB1q4NAeakBkR7NFjjZm31Kh9MMhu MV6oWZ9XUjrFbZ8JydhIj5j3gbYXaJ8nHwltnAU6XBctMJ0l+JrjYUAYYleN2dxHJbEb UYbWtggzhNYp+irCeo4/pubA5mB+R961ySGfc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=mbDvERzySY5uAGfU3YnyW5kfXKKwjtGwVxL6QftAf016IdKd+iZa9GBl4awC8zWBw9 RGB7JUcGaQWE10KP02MdxDC+m847jHxJjAxxahS6PBVGescLSQk9b6xAvpu7rdrfz8yx Nfi03zpA8aQwW3+1iBs3Fwlhzp5XfqcFXPAuI= MIME-Version: 1.0 Received: by 10.231.185.144 with HTTP; Tue, 20 Apr 2010 06:24:53 -0700 (PDT) In-Reply-To: <20100420064006.GE1728@garage.freebsd.pl> References: <20100420064006.GE1728@garage.freebsd.pl> Date: Tue, 20 Apr 2010 07:24:53 -0600 Received: by 10.231.146.146 with SMTP id h18mr1485330ibv.27.1271769893734; Tue, 20 Apr 2010 06:24:53 -0700 (PDT) Message-ID: From: "Jason J. W. Williams" To: Pawel Jakub Dawidek Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: freebsd-current@freebsd.org Subject: Re: ZFS behavior when device disappears 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: Tue, 20 Apr 2010 13:24:56 -0000 Hi Pawel, Thank you very much for the response! Please forgive some of my questions, as I'm a bit unfamiliar with the FreeBSD port. What is the nature of the port? Is it something where each new version of ZFS is a from-scratch effort to some degree? Or is it a point where new ZFS versions are a matter of just making the newer features operational? -J On Tue, Apr 20, 2010 at 12:40 AM, Pawel Jakub Dawidek wro= te: > On Tue, Apr 13, 2010 at 05:39:30PM -0600, Jason J. W. Williams wrote: >> Hello, >> >> Currently, we're an OpenSolaris shop but with the way things are going >> over at Oracle/Sun we're starting to evaluate our options for keeping >> ZFS but moving off Solaris. One of my concerns is that FreeBSD is >> implementing ZFSv14 (ZFS itself is up to v23 I believe). For quite a >> long time, ZFS under Solaris had a real problem with the following >> scenario: >> >> * Hard drive starts to die >> * Controller and SCSI subsystem continue to retry an I/O rather than >> failing fast >> * Even if the I/O does fail fast ZFS doesn't really notice a spike in >> I/O failures and continues to use the drive. >> * Result: I/O on the zpool stalls completely while the I/Os continue >> to be tried against the drive. >> >> This got fixed in later revs of OpenSolaris by enhancements to ZFS and >> greater integration with the Fault Management Architecture (FMA) of >> Solaris...lots of I/Os failing on a drive get communicated to ZFS who >> then offlines the drive out of the pool. >> >> My question is, what is the situation in FreeBSD 8 with ZFS if that >> type of situation occurs? > > I believe FreeBSD does whatever OpenSolaris did for this version of ZFS. > There is nogoing work to bring v24 to FreeBSD. Basic functionality works > already, but a lot work is still needed. At some point I'll see what we > can do about it, because we don't have FMA in FreeBSD and we would need > to find another way to deal with it. I've limited time I can spend on > ZFS right now, so I'm making small steps, but I'm making good progress > too. > > -- > Pawel Jakub Dawidek =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 http://ww= w.wheelsystems.com > pjd@FreeBSD.org =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 http:= //www.FreeBSD.org > FreeBSD committer =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 Am I Ev= il? Yes, I Am! >