Create RAID 5 Arrays with mdadm on Ubuntu 22.04

 To create a RAID 5 array with mdadm on Ubuntu 22.04, first install the mdadm package, identify your available disks using lsblk, and then use the mdadm --create command with the --level=5 and --raid-devices options to build the array, followed by formatting and mounting the new RAID device. 

Steps to Create a RAID 5 Array with mdadm on Ubuntu 22.04: 

1. Install mdadm:

If mdadm is not already installed, open your terminal and run:

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    sudo apt update
    sudo apt install mdadm

 

1. Identify Available Disks:

Use lsblk to list all available disks and identify the ones you want to include in your RAID 5 array. Be careful to select the correct disks, as the process will erase any data on them. 

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    lsblk

1. Create the RAID 5 Array: 

Execute the mdadm --create command to build the RAID 5 array. Replace /dev/md0 with your desired RAID device name (e.g., /dev/md0, /dev/md1, etc.), 3 with the number of devices in your array, and /dev/sda, /dev/sdb, /dev/sdc with the actual device names you identified in the previous step. For RAID 5, you need a minimum of three devices. 

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    sudo mdadm --create --verbose /dev/md0 --level=5 --raid-devices=3 /dev/sda /dev/sdb /dev/sdc

 

1. Verify RAID Creation:

You can check the status of your newly created RAID array with: 

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    sudo mdadm --detail /dev/md0

 

1. Format the RAID 5 Array:

Create a filesystem on the RAID array, for example, ext4: 

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    sudo mkfs.ext4 /dev/md0

 

1. Mount the RAID 5 Array:

Create a mount point and then mount the RAID array: 

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    sudo mkdir /mnt/raid5
    sudo mount /dev/md0 /mnt/raid5

 

1. Configure Automatic Mount on Boot (Optional):

To ensure the RAID array mounts automatically on boot, add an entry to your /etc/fstab file: 

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    echo "/dev/md0 /mnt/raid5 ext4 defaults 0 0" | sudo tee -a /etc/fstab