From mboxrd@z Thu Jan  1 00:00:00 1970
From: NeilBrown <neilb@suse.de>
Subject: Re: Raid5 to another raid level??
Date: Wed, 12 Oct 2011 21:14:41 +1100
Message-ID: <20111012211441.59f32b25@notabene.brown>
References: <-7602537176266265843@unknownmsgid>
	<CAFsPQ__YdDnJw=qgLAq10vRbNPy4B_EhkV4FU0JAfovxnw9TxQ@mail.gmail.com>
	<CAFsPQ__NZPpf1G0MfNFsnLp7d0TrVvSGgN2wNwyeeF_fHDZFAQ@mail.gmail.com>
	<20111012151051.6f03a0e7@notabene.brown>
	<CAFsPQ__r3OX4X_U=f06DCpFMvi2QEKYo9D+N5-SEXpEyRBhR4A@mail.gmail.com>
Mime-Version: 1.0
Content-Type: multipart/signed; micalg=PGP-SHA1;
 boundary="Sig_/5Xz1dBeovhcWUExWTOsdgkK"; protocol="application/pgp-signature"
Return-path: <linux-raid-owner@vger.kernel.org>
In-Reply-To: <CAFsPQ__r3OX4X_U=f06DCpFMvi2QEKYo9D+N5-SEXpEyRBhR4A@mail.gmail.com>
Sender: linux-raid-owner@vger.kernel.org
To: Michael Busby <michael.a.busby@gmail.com>
Cc: john.robinson@anonymous.org.uk, linux-raid@vger.kernel.org
List-Id: linux-raid.ids

--Sig_/5Xz1dBeovhcWUExWTOsdgkK
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

On Wed, 12 Oct 2011 10:25:16 +0100 Michael Busby <michael.a.busby@gmail.com>
wrote:

> Thanks, can i just double check the command with you
>=20
> mdadm --create /dev/md0 --chunk=3D512 --metadata=3D1.0 --assume-clean
> --level=3D5 --raid-devices=3D4 /dev/sde /dev/sdc /dev/sdd /dev/sdb
>=20

Correct.  Of course you have to
   mdadm --stop /dev/md0
first, but you knew that.

NeilBrown


>=20
> On 12 October 2011 05:10, NeilBrown <neilb@suse.de> wrote:
> > On Mon, 10 Oct 2011 22:47:58 +0100 Michael Busby <michael.a.busby@gmail=
.com>
> > wrote:
> >
> >> I have a quick question i remember reading somewhere about not using
> >> metadata version 0.9 with drives larger than 2tb,
> >> > at the moment i have the following
> >> >
> >> > root@BlueBolt:~# cat /proc/mdstat
> >> > Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5]=
 [raid4] [raid10]
> >> > md0 : active raid5 sdd[2] sde[0] sdb[3] sdc[1]
> >> > =A0 =A0 =A0 5860543488 blocks level 5, 512k chunk, algorithm 2 [4/4]=
 [UUUU]
> >> > =A0 =A0 =A0 bitmap: 2/15 pages [8KB], 65536KB chunk
> >> > unused devices: <none>
> >> > root@BlueBolt:~# mdadm --detail /dev/md0
> >> > /dev/md0:
> >> > =A0 =A0 =A0 =A0 Version : 0.90
> >> > =A0 Creation Time : Mon Jul =A04 15:08:38 2011
> >> > =A0 =A0 =A0Raid Level : raid5
> >> > =A0 =A0 =A0Array Size : 5860543488 (5589.05 GiB 6001.20 GB)
> >> > =A0 Used Dev Size : 1953514496 (1863.02 GiB 2000.40 GB)
> >> > =A0 =A0Raid Devices : 4
> >> > =A0 Total Devices : 4
> >> > Preferred Minor : 0
> >> > =A0 =A0 Persistence : Superblock is persistent
> >> > =A0 Intent Bitmap : Internal
> >> > =A0 =A0 Update Time : Mon Oct 10 22:44:11 2011
> >> > =A0 =A0 =A0 =A0 =A0 State : active
> >> > =A0Active Devices : 4
> >> > Working Devices : 4
> >> > =A0Failed Devices : 0
> >> > =A0 Spare Devices : 0
> >> > =A0 =A0 =A0 =A0 =A0Layout : left-symmetric
> >> > =A0 =A0 =A0Chunk Size : 512K
> >> > =A0 =A0 =A0 =A0 =A0 =A0UUID : ddab6c38:dee3ead0:95ba4558:1c9a49ed (l=
ocal to host BlueBolt)
> >> > =A0 =A0 =A0 =A0 =A0Events : 0.2836102
> >> > =A0 =A0 Number =A0 Major =A0 Minor =A0 RaidDevice State
> >> > =A0 =A0 =A0 =A00 =A0 =A0 =A0 8 =A0 =A0 =A0 64 =A0 =A0 =A0 =A00 =A0 =
=A0 =A0active sync =A0 /dev/sde
> >> > =A0 =A0 =A0 =A01 =A0 =A0 =A0 8 =A0 =A0 =A0 32 =A0 =A0 =A0 =A01 =A0 =
=A0 =A0active sync =A0 /dev/sdc
> >> > =A0 =A0 =A0 =A02 =A0 =A0 =A0 8 =A0 =A0 =A0 48 =A0 =A0 =A0 =A02 =A0 =
=A0 =A0active sync =A0 /dev/sdd
> >> > =A0 =A0 =A0 =A03 =A0 =A0 =A0 8 =A0 =A0 =A0 16 =A0 =A0 =A0 =A03 =A0 =
=A0 =A0active sync =A0 /dev/sdb
> >> > which as you can see if using 0.90, i am looking at replacing all th=
e 2tb drives with 3tb versions, would i need to update the metadata version=
? if so how can i go about this?
> >
> > With a really recent kernel (3.1) and recent mdadm (also not released y=
et),
> > 0.90 can go up to 4TB (it has 32 bits to count kilobytes with).
> >
> > Alternately you need to convert to 1.0 metadata.
> >
> > Currently the only way to do this is to 'create' the array again.
> > Be sure to specified the same chunk size, the right metadata, the name =
level
> > and number of disks, and the correct disks in the correct order.
> > An use "--assume-clean". =A0Then check your data is still consistent.
> > With --assume-clean and a read-only mount, no data will actually be cha=
nged,
> > only metadata.
> >
> > NeilBrown
> >
> >


--Sig_/5Xz1dBeovhcWUExWTOsdgkK
Content-Type: application/pgp-signature; name=signature.asc
Content-Disposition: attachment; filename=signature.asc

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.18 (GNU/Linux)

iQIVAwUBTpVonDnsnt1WYoG5AQIgcxAArj7iBqSIdAE0zSSzLphwvPuUD650FIhP
B93+LhQaZ51KTNoGZauTwLdkiKTfRoGAFTzEMjlumgycyCHsqQkRqtBpcUOAcCnH
Jngomuzyo9nlTxiudvjaFecH6POSG/0fzVs6PfnMEQoO7ygPBIiZmIo9twFuEZ5G
H0OEpR/aqfLUt2yFqMKmI7PvWoIUCjOT1XtOtdcw3VaFVMGpO2Vx29rlJ4KMgcug
RuPLJ1c9mu2L48yllmSmp8wQLLSfd+hD5se81rDVnOdd9rxg3+2NIkFusORcHG/i
uI7xJugcmN6DZi+qQWFOD9nNCGIuKDDRwQeWlRhehH+qWYm9cAVY+tT0JBRHCJiX
Zi3mup77eFXdusKf0ivp0LvtDfCYfg6sgpl70tlsgNKT8BHNjMx0cSvDuTOwqmLY
ddst6C4OajGr6kmJw94xOyZquZ3xfRPIEjXpRYk0tTsw+Cac57u5Go0ppHKNzGvS
1eKeQA0q4PX696XkCcauG3rTaZh4Uah6Fn8AjkJ9+IJDPWCaBn+IrHQ1LzgOOYTO
EFCm8TwiAz9k9kTVmWdYpVdwOMg7+IGXe0ndUTgLyxtVs14SCchsr/UwyPfBiJLe
f5oK0CK8Etf8/80y3gi9lCZH3g0WsQOfFlQ0oxkolMYPEGo73ebl+2KiUnX1TXcl
+atyaQPD9ak=
=T+OF
-----END PGP SIGNATURE-----

--Sig_/5Xz1dBeovhcWUExWTOsdgkK--