Backup: Restic

Running `restic` every 5 seconds to back up a MySQL database on a remote Ubuntu server is technically possible but **not recommended** due to:

• Backup overhead (even incremental backups every 5 seconds is resource-intensive).
• Potential data inconsistency and corruption due to overlapping jobs.
• `cron` does not support per-second precision; you'd need `systemd` timers for that.

That said, here's a **safe and practical** version (e.g., every 1–5 minutes), and also a **technical example** for every 5 seconds using `systemd`.

---

1. 1. ✅ Recommended Approach: Every 1 Minute Using systemd Timer

1. 1. 1. Step 1: Create MySQL Dump Script

/usr/local/bin/mysql_backup_restic.sh

```bash

#!/bin/bash

# Settings
MYSQL_USER="root"
MYSQL_PASS="yourpassword"
BACKUP_DIR="/var/backups/mysql"
DUMP_FILE="$BACKUP_DIR/mysql_dump.sql"
RESTIC_REPO="/path/to/restic/repo"
RESTIC_PASSWORD="yourresticpassword"

# Dump MySQL
mkdir -p "$BACKUP_DIR"
mysqldump -u "$MYSQL_USER" -p"$MYSQL_PASS" --all-databases > "$DUMP_FILE"

# Backup with restic
export RESTIC_REPO
export RESTIC_PASSWORD

restic backup "$DUMP_FILE"

```

Make it executable: ```bash chmod +x /usr/local/bin/mysql_backup_restic.sh ```

---

1. 1. 1. Step 2: Create systemd Service

`/etc/systemd/system/mysql-restic-backup.service` ```ini [Unit] Description=Backup MySQL and upload to restic

[Service] Type=oneshot ExecStart=/usr/local/bin/mysql_backup_restic.sh ```

---

1. 1. 1. Step 3: Create Timer (Every Minute)

`/etc/systemd/system/mysql-restic-backup.timer` ```ini [Unit] Description=Run mysql-restic-backup every minute

[Timer] OnBootSec=1min OnUnitActiveSec=1min Unit=mysql-restic-backup.service

[Install] WantedBy=timers.target ```

Enable and start: ```bash sudo systemctl daemon-reexec sudo systemctl enable --now mysql-restic-backup.timer ```

---

1. 1. ⚠️ Every 5 Seconds (Experimental)

Use this only for testing. Real backups this frequently are unsafe.

Edit timer: ```ini [Timer] OnBootSec=5 OnUnitActiveSec=5 Unit=mysql-restic-backup.service ```

This runs the service every 5 seconds. **Warning**: It may trigger overlaps or heavy disk/network usage.

To avoid overlap, you can use a systemd feature to prevent concurrent executions:

Edit the service: ```ini [Service] Type=oneshot ExecStart=/usr/local/bin/mysql_backup_restic.sh ExecStartPre=/bin/sleep 1 ExecStartPost=/bin/sleep 1 TimeoutStartSec=4 ```

---

Would you like a `rest-server` (remote repo) example included too?