setup-raid.sh

#!/bin/bash -ex

# ViciBox v.9.0 RAID1 conversion script

# WARNING! This script is experimental and may result in data loss!
# WARNING! Do not run on a live system without backups!
# WARNING! Script assumes disk layout matches ViciBox v.9.0. MD installer and will not work with other systems.

# Usage: ./setup-raid.sh /dev/sda /dev/sdb
DISK1="${1:-/dev/sda}"
DISK2="${2:-/dev/sdb}"

# TODO: Detect these automatically?
EFI_PART="2"
BOOT_PART="3"
ROOT_PART="4"
SWAP_PART="5"
BOOT_ARRAY="/dev/md3"
ROOT_ARRAY="/dev/md4"



function main {
  if [ efibootmgr 2>/dev/null = 0 ]; then
    echo "System was booted in EFI mode, which is not supported (yet)"
    exit 1
  fi

  checkDiskParams
  removeEfi
  copyPartitionLayout
  setupPartitions
  waitForSync
  updateGrub

  echo "RAID1 setup complete, you need to reboot. Good luck!"
}


function checkDiskParams {
  if [ "$DISK1" = "" -o "$DISK2" = "" -o "$DISK1" = "$DISK2" ]; then
    echo "Usage: $0 /dev/disk1 /dev/disk2"
    exit 1
  fi

  local response

  read -r -p "This script will DESTROY ALL DATA on $DISK2. Are you sure? [y/N] " response
  if [[ ! "${response,,}" =~ ^(yes|y)$ ]]; then
    exit 1
  fi
}


function removeEfi {
  if [ ! "$(mount | grep ' on \/boot\/efi ' --count)" = 0 ]; then
    umount /boot/efi
    commentLine /etc/fstab ' /boot/efi '
  fi
}

function copyPartitionLayout {
  sgdisk "$DISK2" --zap-all
  sgdisk "$DISK1" --replicate="$DISK2"
  sgdisk "$DISK2" --randomize-guids
}

function setupPartitions {
  # SWAP ----------------------------------------
  if [ ! "$(swapon --show=name --noheadings | wc -l)" = "0" ]; then
    mkswap "${DISK2}${SWAP_PART}"
    commentLine /etc/fstab ' swap swap '
    echo "UUID=$(uuidFor "${DISK1}${SWAP_PART}") swap swap defaults 0 0" >> /etc/fstab
    echo "UUID=$(uuidFor "${DISK2}${SWAP_PART}") swap swap defaults 0 0" >> /etc/fstab
  fi

  # ROOT ----------------------------------------
  mdadm --manage "$ROOT_ARRAY" --add "${DISK2}${ROOT_PART}"

  # BOOT ----------------------------------------
  mdadm --zero-superblock "${DISK2}${BOOT_PART}"
  mdadm --create "$BOOT_ARRAY" --level=1 --raid-devices=2 --metadata=1.2 "${DISK2}${BOOT_PART}" missing
  mkfs.ext4 "$BOOT_ARRAY"
  mkdir /tmp/boot
  mount "$BOOT_ARRAY" /tmp/boot
  rsync --archive /boot/ /tmp/boot
  umount /tmp/boot

  # WARNING, from here onwards system wont boot if script does not run to completion
  umount /boot
  mdadm --manage "$BOOT_ARRAY" --add "${DISK1}${BOOT_PART}"
  mdadm --examine --scan > /etc/mdadm.conf

  commentLine /etc/fstab ' /boot '
  echo "UUID=$(uuidFor "$BOOT_ARRAY") /boot ext4 defaults 0 0" >> /etc/fstab
  mount /boot

}

function waitForSync {
  local arrays="$(cat /proc/mdstat | grep 'blocks' --count)"

  while [ ! "$(cat /proc/mdstat | grep '\[UU\]' --count)" = "$arrays" ]; do
    echo "RAID arrays not synced yet, current status:"
    cat /proc/mdstat
    sleep 30
  done
}

function updateGrub {
  echo 'GRUB_DISTRIBUTOR="ViciBox v.9.0"' >> /etc/default/grub

  # Needed to get grub to boot from a RAID1 drive
  echo 'GRUB_PRELOAD_MODULES="diskfilter mdraid1x"' >> /etc/default/grub

  # RAID arrays must be synced before continuing, otherwise grub raises errors
  grub2-mkconfig -o /boot/grub2/grub.cfg
  grub2-install "$DISK1"
  grub2-install "$DISK2"
}

function commentLine {
  local file="$1"
  local search="$(echo "$2" | sed -e 's/[]\/$*.^[]/\\&/g')"   # escape sed search keyword https://stackoverflow.com/a/2705678

  sed -i "s/^.*${search}/#&/g" "$file"
}

function uuidFor {
  blkid -s UUID -o value "$1"
}


main