Backup Strategy with rsync and Cron

You don't need expensive backup software. rsync + cron gives you reliable, automated backups for free. This guide sets up a solid backup strategy you can deploy in minutes.

Prerequisites

• Linux server(s)
• SSH key access between servers (for remote backups)

Step 1: Understand rsync Basics

# Basic local sync
rsync -avz /source/ /destination/
Key flags:
-a  Archive mode (preserves permissions, timestamps, etc.)
-v  Verbose
-z  Compress during transfer
--delete  Remove files in destination that don't exist in source

Step 2: Local Backup Script

Create /usr/local/bin/backup.sh:

#!/bin/bash
Local backup script
DATE=$(date +%Y-%m-%d)
BACKUP_DIR="/backups"
SOURCE_DIRS="/etc /home /var/www /var/lib/postgresql"
LOG="/var/log/backup.log"
echo "=== Backup started: $DATE ===" >> $LOG
for DIR in $SOURCE_DIRS; do
    DEST="$BACKUP_DIR/$(basename $DIR)"
    mkdir -p "$DEST"
    rsync -az --delete "$DIR/" "$DEST/" 2>> $LOG
    echo "Backed up: $DIR -> $DEST" >> $LOG
done
echo "=== Backup completed: $(date) ===" >> $LOG

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

Step 3: Remote Backup

# Sync to a remote server
rsync -avz --delete /var/www/ user@backup-server:/backups/web/
With bandwidth limit (useful for large transfers)
rsync -avz --bwlimit=5000 /data/ user@backup-server:/backups/data/

Step 4: Database Backup

Add database dumps to your script:

# PostgreSQL
pg_dump -U postgres mydb | gzip > "$BACKUP_DIR/db/mydb-$DATE.sql.gz"
MySQL
mysqldump -u root mydb | gzip > "$BACKUP_DIR/db/mydb-$DATE.sql.gz"
Keep only last 14 days of DB dumps
find "$BACKUP_DIR/db/" -name "*.sql.gz" -mtime +14 -delete

Step 5: Automate with Cron

sudo crontab -e

# Daily backup at 3 AM
0 3   * /usr/local/bin/backup.sh
Weekly full backup to remote server on Sunday
0 4   0 rsync -avz --delete /backups/ user@backup-server:/remote-backups/

Step 6: Backup Rotation

Keep multiple versions without filling your disk:

# In your backup script, add rotation
WEEKLY_DIR="$BACKUP_DIR/weekly/$(date +%U)"
MONTHLY_DIR="$BACKUP_DIR/monthly/$(date +%Y-%m)"
Weekly snapshot (keep 4 weeks)
if [ "$(date +%u)" = "7" ]; then
    rsync -az --link-dest="$BACKUP_DIR/daily/" "$BACKUP_DIR/daily/" "$WEEKLY_DIR/"
fi
Clean old weeklies
find "$BACKUP_DIR/weekly/" -maxdepth 1 -mtime +28 -exec rm -rf {} +

Step 7: Verify Your Backups

A backup you haven't tested is not a backup.

# Check backup integrity
rsync -avnc /source/ /backups/source/
-n = dry run, -c = checksum comparison
Test database restore
gunzip -c backup.sql.gz | psql -U postgres testdb

The 3-2-1 Rule

• 3 copies of your data
• 2 different storage media
• 1 offsite copy

Conclusion

This simple setup gives you automated, reliable backups. The most common backup failure is never testing your restores — schedule a monthly restore test and you'll sleep much better.