From owner-freebsd-questions@FreeBSD.ORG Tue Dec 3 09:26:11 2013 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id B3784D9E for ; Tue, 3 Dec 2013 09:26:11 +0000 (UTC) Received: from relaygateway02.edpnet.net (relaygateway02.edpnet.net [212.71.1.211]) by mx1.freebsd.org (Postfix) with ESMTP id 4E3701294 for ; Tue, 3 Dec 2013 09:26:10 +0000 (UTC) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AmIHAIminVJNbXbJ/2dsb2JhbABagwc4g020VAKBF4EYF3SCJQEBBAEjMyMQCw4KAgIFEw4CAg8FJSSIDgqwVolbhmQTBIEpjGprB4JrNYETA5gTAZITgyo7 X-IPAS-Result: AmIHAIminVJNbXbJ/2dsb2JhbABagwc4g020VAKBF4EYF3SCJQEBBAEjMyMQCw4KAgIFEw4CAg8FJSSIDgqwVolbhmQTBIEpjGprB4JrNYETA5gTAZITgyo7 X-IronPort-AV: E=Sophos;i="4.93,816,1378850400"; d="scan'208";a="209607091" Received: from 77.109.118.201.adsl.dyn.edpnet.net (HELO mordor.lan) ([77.109.118.201]) by relaygateway02.edpnet.net with ESMTP/TLS/DHE-RSA-AES256-SHA; 03 Dec 2013 10:10:28 +0100 Date: Tue, 3 Dec 2013 10:26:04 +0100 From: Julien Cigar To: Warren Block Subject: Re: gmirror, gpart and MBR vs GPT in the Handbook Message-ID: <20131203092604.GA86280@mordor.lan> References: <201311301303210813.05DE187E@smtp.24cl.home> <201312011121580096.005D00FB@smtp.24cl.home> <20131202103122.GN66981@mordor.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.22 (2013-10-16) Cc: "Mike." , freebsd-questions@freebsd.org X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 03 Dec 2013 09:26:11 -0000 On Mon, Dec 02, 2013 at 08:56:13AM -0700, Warren Block wrote: > On Mon, 2 Dec 2013, Julien Cigar wrote: > > > If you want to use GPT with gmirror you may want to mirror each > > partition instead of the whole disk. > > > > For example on my box I have the following: https://dpaste.de/Rb3S > > There are a couple of potential problems with that. The big one is when > a disk fails and is replaced. If you're not careful, the rebuild of all > those mirrored partitions will start at the same time. Head contention > will bring that to a near-standstill. It also puts a heavy load on the > drive that still works. Hopefully it is not the same model and age as > the one that failed, or its "warranty timer" may also be close to > expiring. That's true, I turned off autosynchronization of stale components to avoid this kind of bad scenario .. > > A less-serious problem is that only the partitions are mirrored. That > leaves out metadata like the partition tables and bootcode, but those > typically do not change very often and might not be a problem. The > admin has to remember to manually install such things on a new > replacement disk, though. It's just a matter of gpart backup / gpart restore, right ? -- No trees were killed in the creation of this message. However, many electrons were terribly inconvenienced.