Overview

Cron is the standard Linux scheduler. By adding a cron job you can run a backup script unattended — for example, every night at 02:30 — so you never rely on remembering to do it manually. This article shows how to wrap an rsync backup in a script and schedule it.

Before you begin

• A working manual backup command (see [Backing up your server with rsync]).
• Shell access with sudo, and a text editor.
• An ALYPOD Storage Box or S3 bucket as the destination.

Steps

1. Create a script at /usr/local/bin/alypod-backup.sh and make it executable:

```bash

!/usr/bin/env bash

set -euo pipefail

LOG=/var/log/alypod-backup.log DEST="[email protected]:/backup/server1/" DATE="$(date +%F)"

echo "=== Backup started $DATE ===" >> "$LOG" rsync -avz --delete \ --exclude '/cache/' --exclude '*.sock' \ /var/www /etc \ "$DEST" >> "$LOG" 2>&1 echo "=== Backup finished $(date +%F' '%T) ===" >> "$LOG" ```

bash sudo chmod +x /usr/local/bin/alypod-backup.sh

1. Test it manually before scheduling:

bash sudo /usr/local/bin/alypod-backup.sh tail -n 20 /var/log/alypod-backup.log

1. Open the crontab for root:

bash sudo crontab -e

1. Add a schedule. This runs daily at 02:30 and emails output if MAILTO is set:

cron 30 2 * * * /usr/local/bin/alypod-backup.sh >/dev/null 2>&1

1. Save and exit. Confirm the entry was stored:

bash sudo crontab -l

1. Check that the cron daemon is running and enabled:

bash systemctl status crond 2>/dev/null || systemctl status cron

Troubleshooting

• Problem: Job never runs. Solution: Ensure the cron service is active and the script path is absolute. journalctl -u cron shows execution errors.
• Problem: "Permission denied" placing the SSH key. Solution: Cron runs with a minimal environment; specify the key explicitly with -e "ssh -i /root/.ssh/alypod_backup" inside the rsync command.
• Problem: Overlapping runs on large datasets. Solution: Use flock: flock -n /tmp/backup.lock /usr/local/bin/alypod-backup.sh.
• Problem: No output/log. Solution: Redirect stdout and stderr inside the script, as shown, because cron discards them by default.

Related articles

• [Backing up your server with rsync]
• [Restoring data from a backup]
• [Backup best practices (the 3-2-1 rule)]