Automating CD Backups with CD2ISO ScriptsCreating automated backups of optical media (CDs, DVDs) is a practical way to preserve software, music, photos, and archived data. This guide explains how to use CD2ISO and simple scripts to automate ripping CDs into ISO image files on Linux and macOS systems. It covers prerequisites, step-by-step scripting examples, scheduling, error handling, verification, and best practices for storage and maintenance.
What is CD2ISO?
CD2ISO is a lightweight command-line utility that extracts the data track from an optical disc and writes it into an ISO image file. Unlike full-featured disc-ripping suites, CD2ISO focuses on straightforward data duplication, making it well-suited for automated workflows and scripting.
Why automate CD backups?
- Preserve aging optical media prone to scratches and degradation.
- Save time when dealing with many discs.
- Ensure consistent, reproducible backups (useful for archives and audits).
- Integrate disc imaging into broader backup and archival systems.
Prerequisites
- A system with an optical drive (USB or built-in).
- CD2ISO installed. On many Linux distributions, you can install via package manager (e.g., apt, yum); on macOS you may need to build from source or use Homebrew if available.
- Scripting environment (bash/sh, Python, or similar).
- Adequate storage for ISO images and a destination directory or external drive.
- Optional: checksum tools (md5sum, sha256sum), logging utilities, and cron or systemd for scheduling.
Basic CD2ISO usage
The core CD2ISO command typically reads from the device (for example, /dev/cdrom or /dev/sr0) and writes an ISO file:
cd2iso /dev/sr0 /path/to/output.iso Check your system’s device node for the optical drive (use dmesg, lsblk, or diskutil on macOS). Some systems require read permissions or root privileges to access the device.
Example 1 — Simple bash script for a single-disc backup
This script prompts for an output filename and runs cd2iso, then verifies the ISO using sha256sum.
#!/bin/bash set -euo pipefail DEVICE="/dev/sr0" # adjust to your system OUTDIR="$HOME/iso_backups" mkdir -p "$OUTDIR" read -p "Enter output filename (without .iso): " name OUTFILE="$OUTDIR/${name}.iso" echo "Ripping $DEVICE to $OUTFILE..." sudo cd2iso "$DEVICE" "$OUTFILE" echo "Calculating checksum..." sha256sum "$OUTFILE" > "${OUTFILE}.sha256" echo "Done. ISO saved to $OUTFILE" Notes:
- Uses sudo for device access; adapt permissions as needed.
- Creates a checksum file for later verification.
Example 2 — Batch script to rip multiple discs automatically
This version expects each disc to be labeled when inserted and uses the disc volume label to name the ISO. It waits for a disc to be inserted and rips repeatedly until interrupted.
#!/bin/bash set -euo pipefail DEVICE="/dev/sr0" OUTDIR="$HOME/iso_backups" mkdir -p "$OUTDIR" trap 'echo "Interrupted. Exiting."; exit 0' SIGINT SIGTERM while true; do echo "Waiting for disc in $DEVICE..." # Wait for media (polling) while ! lsblk "$DEVICE" | grep -q 'rom'; do sleep 1; done # Try to read volume label (uses blkid or udisksctl) LABEL=$(blkid -o value -s LABEL "$DEVICE" 2>/dev/null || true) if [ -z "$LABEL" ]; then echo "No label detected. Using timestamp..." LABEL=$(date +"disc_%Y%m%d_%H%M%S") fi OUTFILE="$OUTDIR/${LABEL}.iso" echo "Ripping to $OUTFILE..." sudo cd2iso "$DEVICE" "$OUTFILE" || { echo "cd2iso failed"; continue; } sha256sum "$OUTFILE" > "${OUTFILE}.sha256" echo "Ripped $OUTFILE" echo "Ejecting disc..." sudo eject "$DEVICE" sleep 2 done Caveats:
- Device detection method may vary; on some systems you must poll mount status or use udev events instead.
- For audio CDs, cd2iso may not produce standard ISO; specialized tools (cdparanoia, cdrdao) are better.
Example 3 — Python wrapper with logging and retry
A Python script can add structured logging, retries, and integration with network storage.
#!/usr/bin/env python3 import subprocess, time, logging, os, sys from pathlib import Path DEVICE = "/dev/sr0" OUTDIR = Path.home() / "iso_backups" OUTDIR.mkdir(parents=True, exist_ok=True) logging.basicConfig(filename=OUTDIR / "cd2iso.log", level=logging.INFO, format="%(asctime)s %(levelname)s: %(message)s") def run_cmd(cmd, retries=2, delay=5): for attempt in range(retries+1): try: subprocess.run(cmd, check=True) return True except subprocess.CalledProcessError as e: logging.warning("Command failed: %s (attempt %d)", cmd, attempt+1) if attempt < retries: time.sleep(delay) return False def get_label(): try: out = subprocess.check_output(["blkid", "-o", "value", "-s", "LABEL", DEVICE]) return out.decode().strip() except subprocess.CalledProcessError: return None label = get_label() or time.strftime("disc_%Y%m%d_%H%M%S") outfile = OUTDIR / f"{label}.iso" logging.info("Starting rip: %s -> %s", DEVICE, outfile) if run_cmd(["sudo", "cd2iso", DEVICE, str(outfile)]): run_cmd(["sha256sum", str(outfile), ">", str(outfile) + ".sha256"], retries=0) logging.info("Rip complete: %s", outfile) else: logging.error("Rip failed for %s", DEVICE) sys.exit(1) Note: Running shell redirection (>) via subprocess.run needs shell=True or handle file writing in Python; adjust accordingly.
Scheduling and automation
- cron (Linux/macOS): run scripts at system startup or fixed intervals. For event-driven ripping (when a disc is inserted), use udev rules (Linux) or launchd (macOS) to trigger a script.
- systemd: create a service and a path unit that watches for device changes.
- Examples:
- cron: run a script hourly to check for discs.
- udev: trigger a script on MEDIA_CHANGE or add a rule matching the optical drive’s attributes.
Verification and integrity
- Generate checksums (SHA256) for every ISO.
- Optionally use ddrescue for damaged discs to attempt better recovery; then convert rescued data to ISO.
- Keep a metadata file (JSON) with: original disc label, date, checksum, software title, notes about read errors.
Storage, cataloguing, and retention
- Organize ISOs with meaningful filenames or directory structure (by year, category).
- Maintain an index file or simple database (CSV/SQLite) containing metadata for search.
- Keep at least one offsite copy or cloud storage for critical media.
- Periodically verify checksums and migrate storage media before it reaches end-of-life.
Error handling and edge cases
- Audio CDs and mixed-mode discs may not produce usable ISOs with cd2iso; use appropriate tools for audio extraction.
- Scratched or failing discs: try cleaning, use ddrescue with a large block size and multiple passes.
- Permission issues: prefer configuring udev rules or group access so scripts don’t need sudo interactively.
- Device naming differences: support multiple device nodes or scan /dev for optical drives.
Security considerations
- Beware running scripts with sudo; restrict scripts to needed commands and validate inputs to avoid injection.
- Sanitize volume labels or filenames to avoid creating files with unexpected paths.
- Keep backups private or encrypted if they contain sensitive data.
Example metadata JSON template
{ "filename": "Ubuntu_20.04.iso", "label": "Ubuntu 20.04 LTS", "date_ripped": "2025-09-02T14:30:00Z", "checksum_sha256": "abc123...", "source_device": "/dev/sr0", "notes": "Successful rip, no errors." } Best practices checklist
- Use checksums for integrity.
- Log all operations and errors.
- Automate ejecting and prompting to reduce manual steps.
- Handle label/name sanitization.
- Plan storage and offsite redundancy.
Automating CD backups with CD2ISO scripts gives a reliable, scriptable approach to preserving optical media. With checksums, logging, and thoughtful scheduling, you can build a system that minimizes manual work while maximizing archival reliability.
Leave a Reply