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If you run a Linux server or workstation, the file system is not just a place where “park” file, but your first line of defense against data corruption. Today we talk about Btrfs, un file system copy-on-write (CoW) which offers native tools to manage integrity and redundancy.

1. Data integrity: Lo scrub

Unlike Ext4, Btrfs calculates a checksum for each block of data. It Scrub it is the process that reads all the contents and checks the consistency of these checksums.

# Avvia lo scrub in background
sudo btrfs scrub start /mount/point

# Controlla lo stato del processo
sudo btrfs scrub status /mount/point

Note: This is a raid 1, scrub will automatically repair corrupt files using healthy copy.

2. RAID 1: The basis of security

Btrfs manages RAID flexibly. To add a second disk and convert the system to RAID 1:

# Aggiungi il nuovo disco
sudo btrfs device add /dev/sdb /mount/point

# Converti i dati e i metadati
sudo btrfs balance start -dconvert=raid1 -mconvert=raid1 /mount/point

3. Snapshot: Your “cancel button”

Snapshots are instant. If an update breaks your system, you can go back in seconds:

# Crea uno snapshot di sola lettura
sudo btrfs subvolume snapshot -r / /snapshots/root-backup-data

4. Emergency management

In case of serious errors, usa btrfs check, but be careful: never use the flag --repair as a first move. It's often best to try one first btrfs restore to recover files on an external drive.

Remember: Btrfs does not replace an external backup, but it makes your local infrastructure incredibly more resilient.