From mboxrd@z Thu Jan  1 00:00:00 1970
From: Phil Turmel <philip@turmel.org>
Subject: Re: Raid 5 to 6 migration
Date: Fri, 01 Feb 2013 12:50:45 -0500
Message-ID: <510C0075.9010908@turmel.org>
References: <BLU0-SMTP433B0BCF64D448CC81098D2C91C0@phx.gbl>
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Return-path: <linux-raid-owner@vger.kernel.org>
In-Reply-To: <BLU0-SMTP433B0BCF64D448CC81098D2C91C0@phx.gbl>
Sender: linux-raid-owner@vger.kernel.org
To: Dominique <dcouot@hotmail.com>
Cc: linux-raid mailing list <linux-raid@vger.kernel.org>
List-Id: linux-raid.ids

On 02/01/2013 12:17 PM, Dominique wrote:
> Hi list,
> 
> I was wondering what would be the best way to convert a 6 hdd raid 5 to
> raid 6. Ideally without having to reformat everything and lose all the
> data in the process. I have backups of the data but I don't look forward
> reinstalling everything on that server.

1) Add a seventh drive to the system.

You can do this on the run if you have hotplug-capable sata ports or sas
ports.

2) Add that drive to the array w/ "mdadm --add"
3) Convert array to raid6 w/ "mdadm --grow --level=raid6"

You can do 2 & 3 on the run.

4) Monitor /proc/mdstat to see when it finishes.

HTH,

Phil