BorgBackup: Incremental and Deduplicated Backup

# Ubuntu / Debian
apt install borgbackup -y

# CentOS / AlmaLinux
dnf install borgbackup -y

# Verify
borg --version

# Local repository (on disk or external mount)
borg init --encryption=repokey /mnt/backup/my-server

# Remote repository via SSH (on another server)
borg init --encryption=repokey user@backup-server:/path/to/repo

# Create an archive (snapshot) of the server
borg create \
  --stats \
  --progress \
  --compression lz4 \
  /mnt/backup/my-server::backup-{now:%Y-%m-%d} \
  /etc \
  /home \
  /root \
  /var/www \
  /var/lib/mysql \
  --exclude /var/lib/mysql/*.pid \
  --exclude /home/*/.cache \
  --exclude /root/.cache

cat > /usr/local/bin/borg-backup.sh << 'SCRIPT'
#!/bin/bash

# Configuration
REPO="/mnt/backup/my-server"
export BORG_PASSPHRASE="your_passphrase"

# Log
LOG="/var/log/borg-backup.log"
exec >> $LOG 2>&1
echo "=== Backup started: $(date) ==="

# Create the backup
borg create \
  --stats \
  --compression lz4 \
  "$REPO::backup-{now:%Y-%m-%d_%H%M}" \
  /etc /home /root /var/www /var/lib/mysql \
  --exclude '/home/*/.cache' \
  --exclude '/root/.cache' \
  --exclude '*.pyc' \
  --exclude '*.log'

BACKUP_EXIT=$?

# Pruning: maintain retention policy
borg prune \
  --keep-daily 7 \
  --keep-weekly 4 \
  --keep-monthly 6 \
  "$REPO"

PRUNE_EXIT=$?

echo "=== Backup completed: $(date) (backup: $BACKUP_EXIT, prune: $PRUNE_EXIT) ==="
SCRIPT

chmod +x /usr/local/bin/borg-backup.sh

echo "0 2 * * * root /usr/local/bin/borg-backup.sh" > /etc/cron.d/borg-backup

# Configure SSH keys without password for backup
ssh-keygen -t ed25519 -f /root/.ssh/id_borg -N ""
ssh-copy-id -i /root/.ssh/id_borg.pub user@backup-server

# Init the remote repo
BORG_PASSPHRASE="passphrase" borg init \
  --encryption=repokey \
  --rsh "ssh -i /root/.ssh/id_borg" \
  user@backup-server:/backup/my-server

# Backup to remote repo
borg create \
  --rsh "ssh -i /root/.ssh/id_borg" \
  user@backup-server:/backup/my-server::backup-{now:%Y-%m-%d} \
  /etc /home /root /var/www

# List all archives in the repository
borg list /mnt/backup/my-server

# List files in a specific archive
borg list /mnt/backup/my-server::backup-2025-01-15

# Archive info (sizes, deduplication)
borg info /mnt/backup/my-server::backup-2025-01-15

# Verify repository integrity
borg check /mnt/backup/my-server

# Restore entire archive to current directory
cd /tmp/restore
borg extract /mnt/backup/my-server::backup-2025-01-15

# Restore only a specific file or folder
borg extract /mnt/backup/my-server::backup-2025-01-15 etc/nginx/nginx.conf

# Restore to specific directory
borg extract --destination /tmp/restore /mnt/backup/my-server::backup-2025-01-15 var/www/html