raid1 boots with one disk only

DISCUSSION Christian Mueller 2 participants 2 messages Mar 4, 2005 MD RAID

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Christian Mueller

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2005-03-04 14:01 UTC #0 lore raw

Hi Steve!

How do you boot this beast (Bootloader)?
On what partition/md is actually /boot?

Quoted 9 lines · Steve Kwee

..
mdadm -E results in an error message complaining about a missing superblock (see 4.)
..
-----------------------------
4. mdadm -E /dev/md1
-----------------------------
mdadm: No super block found on /dev/md1 (Expected magic a92b4efc, got f1800828)

'man mdadm' shows the following

-E, --examine
Print content of md superblock on device(s).
^^^^^^^^^
So, this works not against an md array.

Cheers, Chris

Signature · 4 lines

# Christian Mueller                   email: <[email protected]>
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Steve Kwee

2005-03-04 14:51 UTC #1 lore raw

Quoted 16 lines · Christian Mueller <christian.mueller1 <at> gmx.de> writes:

Hi Steve!
How do you boot this beast (Bootloader)?
On what partition/md is actually /boot?
Quoted 9 lines · Steve Kwee
..
mdadm -E results in an error message complaining about a missing superblock (see 4.)
..
-----------------------------
4. mdadm -E /dev/md1
-----------------------------
mdadm: No super block found on /dev/md1 (Expected magic a92b4efc, got f1800828)

Quoted 9 lines

'man mdadm' shows the following
-E, --examine
Print content of md superblock on device(s).
^^^^^^^^^
So, this works not against an md array.
Cheers, Chris

There is another raid device /dev/md0 on the same set of disks which has the kernel on it. The kernel is booted with grub /dev/md0 works as expected /dev/md1 does not.
I have attached fstab and menu.lst (1., 2.)

I followed the description found at

http://nickdafish.com/public/HowToRaid

to set things up.

------------------------------------------------------
1. /etc/fstab
-----------------------------------------------
# /etc/fstab: static file system information.
#

# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    defaults        0       0
/dev/hda3       none            swap    sw              0       0
/dev/md0        /boot           reiserfs defaults        0       2
/dev/md1        /               reiserfs defaults        0       2

------------------------------------------------------
2. less /boot/grub/menu.lst
------------------------------------------------------
timeout 8

# By default, boot the first entry.
default 0

# Fallback to the second entry.
fallback 1

# raid
##########################################
title Ubuntu Linux (Kernel hd0, Root /dev/md1)
        kernel  (hd0,0)/vmlinuz-2.6.8.1-3-386 root=/dev/md1 ro splash
        initrd  (hd0,0)/initrd.img-2.6.8.1-3-386
        savedefault
        boot

title Ubuntu Linux (Kernel hd1, Root /dev/md1)

        kernel  (hd1,0)/vmlinuz-2.6.8.1-3-386 root=/dev/md1 ro splash
        initrd  (hd1,0)/initrd.img-2.6.8.1-3-386
        savedefault
        boot

# single user
##########################################
title Ubuntu Linux single (Kernel hd0, Root /dev/md1)
        kernel  (hd0,0)/vmlinuz-2.6.8.1-3-386 root=/dev/md1 ro single
        initrd  (hd0,0)/initrd.img-2.6.8.1-3-386
        savedefault
        boot

title Ubuntu Linux single (Kernel hd1, Root /dev/md1)

        kernel  (hd1,0)/vmlinuz-2.6.8.1-3-386 root=/dev/md1 ro single
        initrd  (hd1,0)/initrd.img-2.6.8.1-3-386
        savedefault
        boot