From owner-freebsd-fs@FreeBSD.ORG Fri Sep 17 08:59:40 2010 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 BE4F8106564A for ; Fri, 17 Sep 2010 08:59:40 +0000 (UTC) (envelope-from alexander@leidinger.net) Received: from mail.ebusiness-leidinger.de (mail.ebusiness-leidinger.de [217.11.53.44]) by mx1.freebsd.org (Postfix) with ESMTP id 508648FC15 for ; Fri, 17 Sep 2010 08:59:39 +0000 (UTC) Received: from outgoing.leidinger.net (p57B3ADE4.dip.t-dialin.net [87.179.173.228]) by mail.ebusiness-leidinger.de (Postfix) with ESMTPSA id 9D18884400D; Fri, 17 Sep 2010 10:59:36 +0200 (CEST) Received: from webmail.leidinger.net (webmail.leidinger.net [192.168.1.102]) by outgoing.leidinger.net (Postfix) with ESMTP id 82E7423C7; Fri, 17 Sep 2010 10:59:33 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=Leidinger.net; s=outgoing-alex; t=1284713973; bh=Uq5m2Q+FnH7KSXxkqZhJj9C64KsAZnSBOlS9G+JZgRg=; h=Message-ID:Date:From:To:Cc:Subject:References:In-Reply-To: MIME-Version:Content-Type:Content-Transfer-Encoding; b=gabsnbsjlmTfqfLDt6cvhMDTnGS/JWZFjm6BYWMa6XzacP7viuS0jJKmzmchwWwD5 NKYpqISEPmiNp1YDuvDur3Ikfy6G0jDC0TFPLDgzHelOe8C+OPrRoHVhxJFT8EcPxp 7NWSP3W2hlWu7E8kcClsxhnddJ6ORITCFmOe2Tzv1IpC/rQPhvXquO0s0T1Efgxye2 k9XBSPm7LRsLPKnht9aE4XyzsHfe11NzzaKAs/1gH4NBYPBStT61kJTXSYFPBVVsbe HrgQcTaCG6w7CM0Su6CpKYHeMS0N7fACMAGVjNpNrgUXhXoKclQJxAMrvx8EpyKHZ4 Gj/blN2PtoUSQ== Received: (from www@localhost) by webmail.leidinger.net (8.14.4/8.13.8/Submit) id o8H8xWKm050598; Fri, 17 Sep 2010 10:59:32 +0200 (CEST) (envelope-from Alexander@Leidinger.net) Received: from pslux.ec.europa.eu (pslux.ec.europa.eu [158.169.9.14]) by webmail.leidinger.net (Horde Framework) with HTTP; Fri, 17 Sep 2010 10:59:32 +0200 Message-ID: <20100917105932.2049587u8fwz4pog@webmail.leidinger.net> Date: Fri, 17 Sep 2010 10:59:32 +0200 From: Alexander Leidinger To: gil@vidals.net, Gil Vidals References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; DelSp="Yes"; format="flowed" Content-Disposition: inline Content-Transfer-Encoding: 7bit User-Agent: Dynamic Internet Messaging Program (DIMP) H3 (1.1.4) X-EBL-MailScanner-Information: Please contact the ISP for more information X-EBL-MailScanner-ID: 9D18884400D.A8165 X-EBL-MailScanner: Found to be clean X-EBL-MailScanner-SpamCheck: not spam, spamhaus-ZEN, SpamAssassin (not cached, score=-1.1, required 6, autolearn=disabled, ALL_TRUSTED -1.00, DKIM_SIGNED 0.10, DKIM_VALID -0.10, DKIM_VALID_AU -0.10) X-EBL-MailScanner-From: alexander@leidinger.net X-EBL-MailScanner-Watermark: 1285318777.90982@ssZtouasrrSuV3uyyg4U1A X-EBL-Spam-Status: No X-Mailman-Approved-At: Fri, 17 Sep 2010 10:58:15 +0000 Cc: freebsd-fs@freebsd.org Subject: Re: what happens to pool if ZIL dies on ZFS v14 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: Fri, 17 Sep 2010 08:59:40 -0000 Quoting Gil Vidals (from Thu, 16 Sep 2010 22:18:40 -0700): > I read a forum post claiming that FreeBSD's ZFS v13 will not continue to > function normally when the dedicated ZIL devices dies or goes away. > Apparently the Solaris version of ZFS does support losing the ZIL. So can > somebody confirm what happens in FreeBSD 8.1 (ZFS v14)? > > Here's the forum post: > *If you are going to split the ZIL onto a separate device, then you ***MUST* > ** make it a mirrored vdev. If the ZIL device ever dies, the entire pool > goes with it!! ZFSv13 (in FreeBSD 8) doesn't support the removal of ZIL > devices.* > > http://forums.freebsd.org/showthread.php?t=9859 No matter if it is Solaris or FreeBSD, the _the_ ZIL dies, the pool dies too. For this reason the recommendation is to mirror any additional ZIL device on any System, to prevent a disk-crash to render the pool useless. A completely different matter is that ZIL devices can not be removed ("administratively removed" is different from "suddenly dead", as in the first case the system can move data from the device to be removed away to the real storage space in the pool). This is true even for -current (ATM). There is work on the way to update the ZFS to a version which allows the removal of ZIL devices (and more). Bye, Alexander. -- Stability itself is nothing else than a more sluggish motion. http://www.Leidinger.net Alexander @ Leidinger.net: PGP ID = B0063FE7 http://www.FreeBSD.org netchild @ FreeBSD.org : PGP ID = 72077137