From owner-freebsd-stable@FreeBSD.ORG Thu May 29 12:03:46 2008 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4CDFD106574E; Thu, 29 May 2008 12:03:46 +0000 (UTC) (envelope-from arnaud.houdelette@tzim.net) Received: from alaranth.tzim.net (alaranth.tzim.net [91.121.97.143]) by mx1.freebsd.org (Postfix) with ESMTP id 347478FC0A; Thu, 29 May 2008 12:03:45 +0000 (UTC) (envelope-from arnaud.houdelette@tzim.net) Received: from localhost ([127.0.0.1]) by alaranth.tzim.net with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.69 (FreeBSD)) (envelope-from ) id 1K1gm4-0004Vu-8O; Thu, 29 May 2008 13:58:28 +0200 Message-ID: <483E9A5D.4010702@tzim.net> Date: Thu, 29 May 2008 13:58:21 +0200 From: Arnaud Houdelette User-Agent: Thunderbird 2.0.0.14 (Windows/20080421) MIME-Version: 1.0 To: Pawel Jakub Dawidek References: <48341CF9.3040008@tzim.net> <20080529114556.GC3159@garage.freebsd.pl> In-Reply-To: <20080529114556.GC3159@garage.freebsd.pl> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Authenticated-User: tzim@tzim.net X-Authenticator: plain Cc: freebsd-stable@freebsd.org Subject: Re: ZFS on root and disk write caching. X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 29 May 2008 12:03:46 -0000 Pawel Jakub Dawidek a écrit : > On Wed, May 21, 2008 at 03:00:41PM +0200, Arnaud Houdelette wrote: > >> I'm playing around with ZFS. >> >> Currently, I just use it for storage, with a zpool of 4 sata disks. >> The system and boot disk is still formatted with UFS. >> >> As I'm quite pleased with ZFS features, I'd like to try ZFS on root. The >> ZFS wiki is quite clear on how to proceed : if the boot and root are on >> the same disk, you'll have to use bsd labels. >> >> The thing is, I read somewhere that ZFS doesn't enable write caching on >> drives if not used on whole disks. >> > > This is only the case for Solaris, as it turns off write cache by > default. In FreeBSD we always turn on write cache, so don't worry, it > will just work on FreeBSD. > Thanks for the info. > [...] > >> 3. I'd like to keep the storage pool (zraid1) separated from the system >> pool (just one disk). The wiki states that we may encounter problems >> with more than one pool in use : is it still the case ? >> > > AFAIK it was never the case. Where did you find that information > exactly? I've two systems that have more than one pool configured and > never had any problems. > It's clearly stated in the ZFS page of the FreeBSD Wiki : http://wiki.freebsd.org/ZFSKnownProblems , 3rd entry states : Kernel panic and/or data loss may result when more than one ZPOOL is active / in use. Symptoms: various, including (unverified) possibility of data loss. References: http://lists.freebsd.org/pipermail/freebsd-fs/2008-February/004377.html I'll try for myself then. Arnaud Houdelette