From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tanguy Herrmann Subject: Re: Confusion with setting up new RAID6 with mdadm Date: Fri, 22 Jul 2011 01:08:34 +0000 (UTC) Message-ID: References: <4CE00206.4000301@geograph.co.za> <20101114195036.GA23982@maude.comedia.it> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Luca Berra comedia.it> writes: > > On Sun, Nov 14, 2010 at 05:36:38PM +0200, Zoltan Szecsei wrote: > > *If I have to reformat the drives and redo mdadm --create, other than mdadm > > stop, how can I get rid of all the /dev/md* etc etc so that when I restart > > this exercise, the original bad RAID does not interfere with this new > > attempt? > > mdadm -Ss > mdadm --zero-superblock on each partition > > > > > > *Partition alignment? > > Is this relevant for modern HDs (I'm using 5900rpm Seagate 2TB drives) > for modern hdds with 4k sectors it is > new fdisk and/or parted should already know how to align > in any case, since you want to use the whole space for raid, why create > partitions at all, md works nicely without Hello, first thank you for the interesting topic (because it fits my questions ^^) and for all the participation of this community to this topic ! I've read somewhere (sorry I can't remind it) that the raid still could be unaligned by using the whole disk, and so we had to create a partition aligned (by using fdisk -u, then creating a partition beginning at LBA 64 at least, and that would span on a length multiple of 8. Was it totally wrong ? Tanguy