From owner-freebsd-fs@FreeBSD.ORG Wed Jun 15 13:07:16 2011 Return-Path: Delivered-To: fs@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id DA962106564A; Wed, 15 Jun 2011 13:07:16 +0000 (UTC) (envelope-from gibbs@scsiguy.com) Received: from aslan.scsiguy.com (mail.scsiguy.com [70.89.174.89]) by mx1.freebsd.org (Postfix) with ESMTP id AE4FC8FC14; Wed, 15 Jun 2011 13:07:16 +0000 (UTC) Received: from Justins-MacBook-Pro.local (macbook.scsiguy.com [192.168.0.99]) (authenticated bits=0) by aslan.scsiguy.com (8.14.4/8.14.4) with ESMTP id p5FD8b0q020298 (version=TLSv1/SSLv3 cipher=DHE-RSA-CAMELLIA256-SHA bits=256 verify=NO); Wed, 15 Jun 2011 07:08:38 -0600 (MDT) (envelope-from gibbs@scsiguy.com) Message-ID: <4DF8AE84.9000400@scsiguy.com> Date: Wed, 15 Jun 2011 07:07:16 -0600 From: "Justin T. Gibbs" User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.17) Gecko/20110414 Thunderbird/3.1.10 MIME-Version: 1.0 To: Pawel Jakub Dawidek References: <4DF7E472.9030601@scsiguy.com> <20110615121529.GJ1975@garage.freebsd.pl> In-Reply-To: <20110615121529.GJ1975@garage.freebsd.pl> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.6 (aslan.scsiguy.com [70.89.174.89]); Wed, 15 Jun 2011 07:08:38 -0600 (MDT) Cc: fs@FreeBSD.org Subject: Re: [CFR][ZFS] Allow async event processing with a R/O root FS 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: Wed, 15 Jun 2011 13:07:16 -0000 On 6/15/11 6:15 AM, Pawel Jakub Dawidek wrote: > On Tue, Jun 14, 2011 at 04:45:06PM -0600, Justin T. Gibbs wrote: >> Allow ZFS asynchronous event handling to proceed even if the >> root file system is mounted read-only. This restriction appears >> to have been put in place to avoid errors with updating the >> configuration cache file. However: >> >> o The majority of asynchronous event handling does not involve >> configuration cache file updates. >> o The configuration cache file need not be on the root file system, >> so the check was not complete. > Why is that? I keep cache file on the ZFS root file system. > It is not used by the boot loader, but is loaded by the loader: > > # tail -7 /boot/defaults/loader.conf > You can specify an alternate cache file location that doesn't have to be on the root file system. By "the check was not complete", I mean the "root is R/W" check doesn't ensure that the cache file is located on a file system mounted R/W. -- Justin