Accurate ISO files from CDs
It's quite common to want to make a mountable ISO file from a CD so that you don't have to deal with the hassle of the physical disks. I do this a lot for CDs that come with hardware (e.g. motherboard driver CDs). It's certainly more convenient than having to locate that elusive disk when you're struggling with an old motherboard or sound card.
There is a lot of information given in the references below about the choices behind the best technique. Here, I summarise the a reliable technique for producing verifiable copies.
Begin by finding out the blocksize and count for your source disk:
james@eastlight:~> isoinfo -d -i /dev/cdrom CD-ROM is in ISO 9660 format System id: Volume id: DEFAULT Volume set id: Publisher id: Data preparer id: Application id: NERO BURNING ROM Copyright File id: Abstract File id: Bibliographic File id: Volume set size is: 1 Volume set sequence number is: 1 Logical block size is: 2048 This is the blocksize (bs) Volume size is: 98891 This is the count NO Joliet present NO Rock Ridge present
If you happen to be using Mageia/Mandriva, isoinfo is found in the cdrkit-isotools package.
Next, copy the image from the CD to the hard drive using the pre-determined parameters. if = input file and of = output file:
james@eastlight:~> dd if=/dev/cdrom bs=2048 count=98891 of=~/output.iso 98891+0 records in 98891+0 records out 202528768 bytes (203 MB) copied, 75.1607 s, 2.7 MB/s
Finally, compare the md5sum of both the original disk and the iso file to ensure an accurate copy:
james@eastlight:~> dd if=/dev/cdrom bs=2048 count=98891 | md5sum c14949f4c02633651da7febac335d7f8 - james@eastlight:~> cat ~/output.iso | md5sum c14949f4c02633651da7febac335d7f8 - A match so a good copy
If you ever need to produce a physical CD from your image in future, any good CD burning program should be able to do the task.
A complete description of the process
Detailed information on how to perform coasterless CD burning on linux
First published on 27th January 2013 and last modified on 30th January 2013.