Verify Disc Burns: Data Integrity Checks

TL;DR

Yes! You can check if a burned disc has copied data correctly using checksums (like MD5, SHA-256) or disc imaging tools. This guide shows you how.

How to Verify Disc Burns: Data Integrity Checks

1. Understand the Problem

Burning discs isn’t always perfect. Errors can happen, leading to corrupted files. Checking verifies the burn matched the original data.

2. Checksums – The Quick Method

Checksums create a unique ‘fingerprint’ of your files. Compare the fingerprint before and after burning.

• Step 1: Calculate the Checksum Before Burning

On Windows, you can use PowerShell:

Get-FileHash "pathtoyourfile.iso" -Algorithm MD5

Or for multiple files in a folder:

(Get-ChildItem "pathtoyourfolder" | Get-FileHash -Algorithm MD5).Hash

On Linux/macOS, use the md5sum command:

md5sum path/to/your/file.iso

For SHA-256 (more secure): replace MD5 with SHA256 in the commands above.

Step 2: Calculate the Checksum After Burning

Repeat Step 1, but this time point it at the files on your burned disc. Make sure to mount the disc first if necessary.

Step 3: Compare the Results

The checksums *must* match exactly. If they don’t, the burn is faulty and you should try again with a different disc or lower burning speed.

Disc Imaging – The More Thorough Method

This creates an exact copy of your disc as a single file (an image). You can then verify this image against the original source.

• Step 1: Create a Disc Image

Use software like ImgBurn (Windows, free) or dd (Linux/macOS).

ImgBurn Example: Select ‘Create image file from files/folders’. Choose your source data and output location.

dd Example (Linux/macOS – be *very* careful with this command!):

sudo dd if=/dev/diskX of=disc.iso bs=2048 status=progress

(Replace /dev/diskX with your disc drive – use lsblk or diskutil list to find it!)

Step 2: Verify the Image

Calculate the checksum of both the original source data and the created image file (as in Step 1 of the Checksum method). If they match, your image is good.

Step 3: Burn from the Verified Image

Burn the verified image file to a new disc. This significantly reduces errors compared to burning files directly.

Software Recommendations

• ImgBurn (Windows): Free, powerful for creating and verifying images. https://www.imgburn.com/
• PowerISO (Windows, paid): Another good option with more features.
• dd (Linux/macOS): Command-line tool for creating images – requires caution!

Troubleshooting

• Slow Burning Speed: Lower the burning speed. Higher speeds increase error rates.
• Poor Quality Discs: Use reputable brands. Cheap discs are often unreliable.
• Dirty Drive: Clean your optical drive regularly.