From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 1 Aug 2001 11:00:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 1 Aug 2001 11:00:21 -0400 Received: from stargate.gnyrf.net ([194.165.254.115]:51074 "HELO stargate.gnyrf.net") by vger.kernel.org with SMTP id ; Wed, 1 Aug 2001 11:00:10 -0400 To: Neil Brown Subject: Re: resizing of raid5? Message-ID: <996685021.3b6834dd0829d@stargate.gnyrf.net> Date: Wed, 01 Aug 2001 18:57:01 +0200 (CEST) From: Roger Abrahamsson Cc: Linux Kernel In-Reply-To: <996657922.3b67cb02ba717@stargate.gnyrf.net> <15207.63232.611617.37794@notabene.cse.unsw.edu.au> In-Reply-To: <15207.63232.611617.37794@notabene.cse.unsw.edu.au> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT User-Agent: IMP/PHP IMAP webmail program 2.2.5 X-Originating-IP: 212.32.163.13 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Quoting Neil Brown : > > The only way to resize a raid5 array is to back up, rebuild, and > re-load. Any attempt to re-organise the data, or the linkage, to > avoid this would be more trouble that it is worth. > > NeilBrown Well, the problem is that it's not that easy when you want to backup say 200GB of data to find anyone that can hold it for the day while you do it. Well, at least do it without charge :) Having things offline for up to a few days while you do the rebuild is okay for my case, but the offloading the data is not. If I have understood md and raid5, you create blocks of a fixed size, and calculate the checksum on each "stripe". To rebuild this looks a bit like disk defragmentation to me, or am I totally wrong here?