(unknown)

Hello=2C

I am trying to re-setup my fake-raid (RAID1) volume with LVM2 like setup pr=
eviously. I had been using dmraid on a Lenny installation which gave me (fr=
om memory) a block device like /dev/mapper/isw_xxxxxxxxxxx_ and also a /dev=
/One1TB=2C but have discovered that the mdadm has replaced the older and be=
lieved to be obsolete dmraid for multiple disk/raid support.

Automatically the fake-raid LVM physical volume does not seem to be set up.=
I believe my data is safe as I can insert a knoppix live-cd in the system =
and mount the fake-raid volume (and browse the files). I am planning on per=
haps purchasing another at least 1TB drive to backup the data before trying=
to much fancy stuff with mdadm in fear of loosing the data.

A few commands that might shed more light on the situation:


pvdisplay (showing the /dev/md/[device] not recognized yet by LVM2=2C note =
sdc another single drive with LVM)

--- Physical volume ---
PV Name /dev/sdc7
VG Name XENSTORE-VG
PV Size 46.56 GiB / not usable 2.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 11920
Free PE 0
Allocated PE 11920
PV UUID wRa8xM-lcGZ-GwLX-F6bA-YiCj-c9e1-eMpPdL


cat /proc/mdstat (showing what mdadm shows/discovers)

Personalities :
md127 : inactive sda[1](S) sdb[0](S)
4514 blocks super external:imsm

unused devices:=20


ls -l /dev/md/imsm0 (showing contents of /dev/md/* [currently only one file=
/link ])

lrwxrwxrwx 1 root root 8 Nov 7 08:07 /dev/md/imsm0 -> ../md127


ls -l /dev/md127 (showing the block device)

brw-rw---- 1 root disk 9=2C 127 Nov 7 08:07 /dev/md127




It looks like I can not even access the md device the system created on boo=
t.=20

Does anyone have a guide or tips to migrating from the older dmraid to mdad=
m for fake-raid?


fdisk -uc /dev/md127=A0 (showing the block device is inaccessible)

Unable to read /dev/md127


dmesg (pieces of dmesg/booting)

[  =A0 4.214092] device-mapper: uevent: version 1.0.3
[  =A0 4.214495] device-mapper: ioctl: 4.15.0-ioctl (2009-04-01) initia=
lised: dm-devel@redhat.com
[  =A0 5.509386] udev[446]: starting version 163
[  =A0 7.181418] md: md127 stopped.
[  =A0 7.183088] md: bind
[  =A0 7.183179] md: bind



update-initramfs -u (Perhaps the most interesting error of them all=2C I ca=
n confirm this occurs with a few different kernels)

update-initramfs: Generating /boot/initrd.img-2.6.32-5-xen-amd64
mdadm: cannot open /dev/md/OneTB-RAID1-PV: No such file or directory


Revised my information=2C inital thread on Debian-users thread at:
http://lists.debian.org/debian-user/2010/11/msg01015.html

Thanks for any ones help :)

-M
=

Re:

On Sat, 13 Nov 2010 01:01:47 -0500
Mike Viau wrote:

>=20
> Hello,
>=20
> I am trying to re-setup my fake-raid (RAID1) volume with LVM2 like se=
tup previously. I had been using dmraid on a Lenny installation which g=
ave me (from memory) a block device like /dev/mapper/isw_xxxxxxxxxxx_ a=
nd also a /dev/One1TB, but have discovered that the mdadm has replaced =
the older and believed to be obsolete dmraid for multiple disk/raid sup=
port.
>=20
> Automatically the fake-raid LVM physical volume does not seem to be s=
et up. I believe my data is safe as I can insert a knoppix live-cd in t=
he system and mount the fake-raid volume (and browse the files). I am p=
lanning on perhaps purchasing another at least 1TB drive to backup the =
data before trying to much fancy stuff with mdadm in fear of loosing th=
e data.
>=20
> A few commands that might shed more light on the situation:
>=20
>=20
> pvdisplay (showing the /dev/md/[device] not recognized yet by LVM2, n=
ote sdc another single drive with LVM)
>=20
> --- Physical volume ---
> PV Name /dev/sdc7
> VG Name XENSTORE-VG
> PV Size 46.56 GiB / not usable 2.00 MiB
> Allocatable yes (but full)
> PE Size 4.00 MiB
> Total PE 11920
> Free PE 0
> Allocated PE 11920
> PV UUID wRa8xM-lcGZ-GwLX-F6bA-YiCj-c9e1-eMpPdL
>=20
>=20
> cat /proc/mdstat (showing what mdadm shows/discovers)
>=20
> Personalities :
> md127 : inactive sda[1](S) sdb[0](S)
> 4514 blocks super external:imsm
>=20
> unused devices:=20

As imsm can have several arrays described by one set of metadata, mdadm
creates an inactive arrive just like this which just holds the set of
devices, and then should create other arrays made of from different reg=
ions
of those devices.
It looks like mdadm hasn't done that you. You can ask it to with:

mdadm -I /dev/md/imsm0

That should created the real raid1 array in /dev/md/something.

NeilBrown


>=20
>=20
> ls -l /dev/md/imsm0 (showing contents of /dev/md/* [currently only on=
e file/link ])
>=20
> lrwxrwxrwx 1 root root 8 Nov 7 08:07 /dev/md/imsm0 -> ../md127
>=20
>=20
> ls -l /dev/md127 (showing the block device)
>=20
> brw-rw---- 1 root disk 9, 127 Nov 7 08:07 /dev/md127
>=20
>=20
>=20
>=20
> It looks like I can not even access the md device the system created =
on boot.=20
>=20
> Does anyone have a guide or tips to migrating from the older dmraid t=
o mdadm for fake-raid?
>=20
>=20
> fdisk -uc /dev/md127  (showing the block device is inaccessible)
>=20
> Unable to read /dev/md127
>=20
>=20
> dmesg (pieces of dmesg/booting)
>=20
> [    4.214092] device-mapper: uevent: version 1.0.3
> [    4.214495] device-mapper: ioctl: 4.15.0-ioctl (200=
9-04-01) initialised: dm-devel@redhat.com
> [    5.509386] udev[446]: starting version 163
> [    7.181418] md: md127 stopped.
> [    7.183088] md: bind
> [    7.183179] md: bind
>=20
>=20
>=20
> update-initramfs -u (Perhaps the most interesting error of them all, =
I can confirm this occurs with a few different kernels)
>=20
> update-initramfs: Generating /boot/initrd.img-2.6.32-5-xen-amd64
> mdadm: cannot open /dev/md/OneTB-RAID1-PV: No such file or directory
>=20
>=20
> Revised my information, inital thread on Debian-users thread at:
> http://lists.debian.org/debian-user/2010/11/msg01015.html
>=20
> Thanks for any ones help :)
>=20
> -M
> --
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