Notes on RAID for Ubuntu

Shorthand notes on how to convert a new Ubuntu system to RAID 1

Install Ubuntu Server

System has 12GB of RAM

System has two 250GB drives (actually a 320 and a 250, I ignore the extra space for now)

During installation create 6 partitions on each drive, so that the system can be converted to RAID 1 (mirrored)

1   1GB  /boot     wont be raid, so we can boot!
2  10GB  /raidroot where the system will be eventually
3  10GB  /         initial install location
4        EXT
5  24GB  SWAP      won't be raided, so we will have 48GB of swap
6 200GB /raidvar   will be raided /var partition

Do the installation. After it's done install the package to manage raid

apt-get install mdadm

Create RAID filesystems

In /etc/raidtab

# Root partition will be here
raiddev /dev/md0
        raid-level      1
        nr-raid-disks   2
        nr-spare-disks  0
        persistent-superblock 1
        device          /dev/sda2
        raid-disk       0
        device          /dev/sdb2
        raid-disk       1

# After successfully installing a bootable copy of /dev/sda3 on /dev/md0
# uncomment this to bounce a backup copy of the root to /dev/md1
#raiddev /dev/md1
#        raid-level      1
#        nr-raid-disks   2
#        nr-spare-disks  0
#        persistent-superblock 1
#        device          /dev/sda3
#        raid-disk       0
#        device          /dev/sdb3
#        raid-disk       1

raiddev /dev/md2
        raid-level      1
        nr-raid-disks   2
        nr-spare-disks  0
        persistent-superblock 1
        device          /dev/sda6
        raid-disk       0
        device          /dev/sdb6
        raid-disk       1