User Tools

Site Tools


linux:verify_burned_cd

How to verify a burned CD/DVD?

11.10.2010

These methods implies that you created first a dvd image (.iso).

1. DIFF METHOD

After burning, mount the DVD image somewhere on the disk:

# mount -o ro,loop -t iso9660 /path/to/file.iso /point/mounting

And then check with <i>diff</i>:

# diff -r /point/mounting /media/cdrom 

Note: /media/cdrom could be different. Check your local settings (/media/…)

2. MD5SUM METHOD

You simply compare the md5 sum for image and burned DVD:

# md5sum /path/to/file.iso
50dc0947340b855e28ba4f8c79202f9a /path/to/file.iso

For disk you should know the number of extents written. This number is outputed when you create the dvd image (by mkisofs or genisoimage). Example:

Total translation table size: 0
Total rockridge attributes bytes: 31270
Total directory bytes: 116736
Path table size(bytes): 1010
Max brk space used 42000
2062625 extents written (4028 MB)

And then md5sum on:

# dd if=/dev/cdrom bs=2048 count=2062625 | md5sum
2062625+0 records in
2062625+0 records out
4224256000 bytes (4.2 GB) copied, 517.057 s, 8.2 MB/s
50dc0947340b855e28ba4f8c79202f9a

You should avoid dd if=/dev/cdrom | md5sum because it will return wrong results (this includes also other bits of informations apart for iso image)

3. OTHER TOOLS

dvdisaster dvdisaster stores data on CD/DVD/BD (supported media) in a way that it is fully recoverable even after some read errors have developed. This enables you to rescue the complete data to a new medium.

linux/verify_burned_cd.txt · Last modified: 2013/03/16 17:40 (external edit)