Karmic Koala instructions for reassembling my RAID 5 software array on my Server after reinstalling the OS

I didn’t learn to do this by choice! I mucked up my video configuraiton and couldn’t boot into the gnome… after spending about 4 or 5 hours trying to fix it; I “bit the bullet” and reinstalled ubuntu.

1. I installed mdadm

sudo apt-get install mdadm

2. I (re) assembled the array

sudo mdadm –assemble /dev/md0 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1 /dev/sdf1

3. I got the details of the array

sudo mdadm –detail –scan

Output on this occasion was as follows; do not copy and paste this directly – it will be a different UUID for future arrays I create

ARRAY /dev/md0 level=raid5 num-devices=6 metadata=00.90 UUID=58155936:66553965:01f9e43d:ac30fbff

I found out later that I needed to remove one of the zeroes from the metadata version… when I did a sudo mdadm -D it gave me an error for the version information.

ARRAY /dev/md0 level=raid5 num-devices=6 metadata=0.90 UUID=58155936:66553965:01f9e43d:ac30fbff

4. I copied and pasted the above line into mdadm.conf

sudo nano /etc/mdadm.conf

File now has the following entry:

# definitions of existing MD arrays

ARRAY /dev/md0 level=raid5 num-devices=6 metadata=0.90 UUID=58155936:66553965:01f9e43d:ac30fbff

5. I created somewhere for the array to be mounted

cd /mnt

sudo mkdir raid

6. I wanted the drive to be mounted automaticaly on startup

sudo nano /etc/fstab

7. I added the following line

/dev/md0                /mnt/raid                ext3                defaults                0                0

8. I mounted all arrays without rebooting

sudo mount -a

assemble, Karmic Koala, mdadm, raid, raid5, reassemble, reinstall OS, Ubuntu