From owner-freebsd-questions@FreeBSD.ORG Sat Aug 2 22:41:44 2014 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 BCD4DA76 for ; Sat, 2 Aug 2014 22:41:44 +0000 (UTC) Received: from mail.magehandbook.com (173-8-4-45-WashingtonDC.hfc.comcastbusiness.net [173.8.4.45]) by mx1.freebsd.org (Postfix) with ESMTP id 968F62757 for ; Sat, 2 Aug 2014 22:41:43 +0000 (UTC) Received: from [192.168.1.50] (Mac-Pro.magehandbook.com [192.168.1.50]) by mail.magehandbook.com (Postfix) with ESMTP id 3hQgBC0dFJzCS for ; Sat, 2 Aug 2014 18:33:39 -0400 (EDT) Date: Sat, 02 Aug 2014 18:33:38 -0400 From: Daniel Staal To: freebsd-questions@freebsd.org Subject: Re: gvinum raid5 vs. ZFS raidz Message-ID: <2D72AC9FF5B82553FEF7D3EB@[192.168.1.50]> In-Reply-To: <201408020621.s726LsiA024208@sdf.org> References: <201408020621.s726LsiA024208@sdf.org> X-Mailer: Mulberry/4.0.8 (Mac OS X) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 02 Aug 2014 22:41:44 -0000 --As of August 2, 2014 1:21:54 AM -0500, Scott Bennett is alleged to have said: >>> Does not support migration to any other Does not support migration >>> RAID levels or their equivalents. between raidz levels, even by >> >> Correct. Once you have created a vdev, that vdev must remain the same >> type. You can add mirrors to a mirror vdev, but you cannot add drives or >> change raid level to raidz1, raidz2, or raidz3 vdevs. > > Too bad. Increasing the raidz level ought to be not much more > difficult than growing the raidz device by adding more spindles. Doing > the latter ought to be no more difficult that doing it with gvinum's > stripe or raid5 devices. Perhaps the ZFS developers will eventually > implement these capabilities. (A side thought: gstripe and graid3 > devices ought also to be expandable in this manner, although the resulting > number of graid3 components would still need to be 2^n + 1.) --As for the rest, it is mine. There actually is a semi-simple way, even if it's not direct... You can 'send' a ZFS filesystem to a backup drive, and then 'receive' it back to a new pool. It will keep all file and volume level options when you do that, but the pools can be set up differently. It's not something you can do in-place, but it's not hard either. (Basically, it's a simplified 'backup and restore to new setup', but it is majorly simplified.) Daniel T. Staal --------------------------------------------------------------- This email copyright the author. Unless otherwise noted, you are expressly allowed to retransmit, quote, or otherwise use the contents for non-commercial purposes. This copyright will expire 5 years after the author's death, or in 30 years, whichever is longer, unless such a period is in excess of local copyright law. ---------------------------------------------------------------