Transitioning From a Single Disk to Raid-1 On Ubuntu Linux

Migrating from a single disk setup to RAID-1 on Ubuntu Linux involves a series of steps to ensure a smooth transition. Here’s a basic guide:

1. Backup Data:
   • Before making any changes, back up your important data. While the process is generally safe, it’s always wise to have a backup in case of unexpected issues.
2. Install mdadm:
   • Ensure that the mdadm (Multiple Device Admin) package is installed. This tool is used for managing Linux software RAID devices.
   sudo apt-get install mdadm

3. Identify Disks:
   • Identify the disks you want to use for the RAID-1 array. You can use tools like fdisk or lsblk to list available disks.
   sudo fdisk -l

4. Partition Disks:
   • Use fdisk or parted to create partitions on the new disks. Make sure the partitions have the same size.
5. Create RAID-1 Array:
   • Use mdadm to create the RAID-1 array. Replace /dev/sdX1 and /dev/sdY1 with your actual partition names.
   sudo mdadm --create --verbose /dev/md0 --level=1 --raid-devices=2 /dev/sdX1 /dev/sdY1

6. Monitor RAID Status:
   • Monitor the RAID array creation process and check its status.
   watch cat /proc/mdstat

   Once the process is complete, you should see a line indicating that the RAID array is active and synced.

7. Create Filesystem:
   • Create a filesystem on the new RAID array.
   sudo mkfs.ext4 /dev/md0

8. Mount RAID Array:
   • Create a mount point and mount the RAID array.
   sudo mkdir /mnt/raid sudo mount /dev/md0 /mnt/raid

9. Update /etc/mdadm/mdadm.conf:
   • Update the mdadm.conf file to include information about your RAID array.
   sudo mdadm --detail --scan | sudo tee -a /etc/mdadm/mdadm.conf

10. Update /etc/fstab:
    • Update the /etc/fstab file to automatically mount the RAID array on boot.
    echo '/dev/md0 /mnt/raid ext4 defaults,nofail,discard 0 0' | sudo tee -a /etc/fstab

11. Reboot:
    • Reboot your system to ensure that the RAID array is mounted correctly.

sudo reboot

12. Verify:
    • After rebooting, check the RAID array status.

cat /proc/mdstat

Ensure that the array is still active and synced.

Always adapt the commands according to your specific disk names and requirements. This guide provides a basic overview, and it’s essential to understand the specifics of your system before proceeding.