From mboxrd@z Thu Jan 1 00:00:00 1970 From: maarten Subject: Re: Checking if RAID does work? Date: Wed, 19 Jan 2005 22:59:46 +0100 Message-ID: <200501192259.46359.maarten@ultratux.net> References: <20050117010355.GH347@unthought.net> <200501192217.29258.maarten@ultratux.net> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Content-Disposition: inline Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Wednesday 19 January 2005 22:22, M=E5ns Rullg=E5rd wrote: > maarten writes: > > To the OP: Yes, every part of a raid-1 array (but only a raid-1 > > array) will / should be mountable and have the same filesystem as > > the array has. HOWEVER you should never ever mount the array AT TH= E > > SAME TIME as one of its underlying devices! Always umount first, > > and only then mount the other. > > Furthermore, never ever mount a raid-1 component alone in read-write > mode. Modifying the mirrors individually will almost certainly resul= t > in breakage when the array is activated again. Speaking from personal experience, I _think_ that modifying a drive tha= t's=20 part of an array gets noticed by md (somehow). At least it always lead= to a=20 mirror breakage with me, and thus a re-add and a resync was in order. I'm not sure if it really does that, and neither how it is done, but I'= m led=20 to believe it does get noticed. Maybe md (or the kernel?) writes a mark= er=20 just before deactivation which signifies "drive was shutdown @..." ? OTOH, I've also seen that I just modified /etc/fstab on hda1 to reflect= that=20 not /de/hda1 was root, but /dev/md0 instead, only to find that after a=20 reboot /dev/md0 is _indeed_ now mounted as root, but that those recent=20 changes in /fstab are gone. So... maybe I'm just losing my head. (-: Maarten --=20 - To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html