mdadm array disappears

[cburwell]

I am trying to setup a new RAID 1 array with two 500GB disks. I read up on everything, and I know I setup the array properly, but I have several problems.

1) When I go to issue the following commands:

echo "DEVICE partitions" > mdadm.conf
mdadm --detail --scan >> mdadm.conf

I get a "permission denied" error. I have issued them using sudo, but I still get the same results.

2) The biggest problem is that when I restart my array does not automatically reappear. This is a problem since the data will be shared VIA Samba across a network.

In order to get the array back I have to do the following:

sudo mdadm -A /dev/md0 /dev/sda1 /dev/sdb1
sudo cat /proc/mdstat (I do this to make sure the array is now showing, and it is)
sudo /etc/init.d/samba restart

This will get me where I need to be, however I may not be around to do this if there is a power failure. Does anyone know how to get an mdadm array to mount automatically at boot time?

I have also added the following to my /etc/fstab file, but no dice:

/dev/md0 /var/shared ext3 defaultS 0 0

[cburwell]

I have created a shell script that will reactivate and remount the array at boot time (I installed it using update-rc.d). I have included the code below, which some people may find handy.

Please note that you will have to edit this script, since I have tailored it for my needs. If you understand how to do everything by hand, editing the script should be cake. E-mail me if you have any questions about the script

#!/bin/bash
#
# Author: Chris Burwell (cburwell@comcast.net)
# Created: April 03, 2007
# Updated: April 04, 2007
# Function: Used to mount a mdadm raid array to
#               a Debian system.
#
#
# Start functiomn
#
start() {
        # Check if md0 device is active
        ARRAYTEST=$(echo $(awk '/md0/' /proc/mdstat))
        if [ -z "$ARRAYTEST" ] ; then
                echo "Re-adding array: /dev/md0" &
                mdadm -A /dev/md0 /dev/sda1 /dev/sdb1
        else
                echo "RAID array exsists!" &
        fi

        # Check if array is mounted
        MOUNTTEST=$(echo $(mount|awk '/md0/'))
        if [ -z "$MOUNTTEST" ] ; then
                # Mount array
                echo "Mounting /dev/md0 to /var/shared" &
                mount /dev/md0 /var/shared
        else
                echo "Array has already been mounted!" &
                echo "Exiting!" &
        fi

        # Restart Samba
        echo "Restarting samba with: /etc/init.d/samba" &
        /etc/init.d/samba restart
}

#
# Stop function
#
stop() {
        # Unmount array
        echo "Unmounting: /var/shared" &
        umount /var/shared
}

#
# Status function
#
status() {
        # Print array information
        echo "ARRAY INFORMATION" &
        echo "------------------" &

        # Print mount information
        echo "ARRAY MOUNT INFORMATION" &
        echo "------------------" &
}
case "$1" in
        start)
                start
                ;;
        stop)
                stop
                ;;
        restart)
                stop
                start
                ;;
        status)
                status
                ;;
        *)
                echo "Usage: {start|stop|restart|status}"
                exit 1
                ;;
esac
exit

[cjrt35]

OK, I know this is an old thread, but in case anyone else finds it while scratching their head

Note that this I was using Red Hat Enterprise 3 (RHEL3) but I suspect it applies to others as well. However, your milege may vary...

I fixed this problem by doing mkinitrd with the md device running. It appears initrd needs to know you're using md for the autodetect to work.

cd /boot
mkinitrd <initrdname> <kernel-ver>

FFI see man mkinitrd

Chris