Configure software RAID (mdadm) on dedicated server

On a dedicated server with two identical disks, RAID1 mirrors data (not a backup replacement).

📋 Prerequisites

• Two same-size disks (e.g. /dev/sda, /dev/sdb)
• Full backup before changes
• Rescue/KVM access if something goes wrong

Install mdadm

Bash
1sudo apt install -y mdadm

Create RAID1 (example)

⚠️ Destroys disk data. Adjust device names.

Bash
1sudo mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sda /dev/sdb

Filesystem

Bash
1sudo mkfs.ext4 /dev/md0

Persist config

Bash
1sudo mdadm --detail --scan | sudo tee -a /etc/mdadm/mdadm.conf

Monitor

Bash
1cat /proc/mdstat

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More resilient storage! 🚀