How to do it...

In order to create an ISO image from /dev/cdrom, use the following command:

    # cat /dev/cdrom > image.iso

Though this will work, the preferred way to create an ISO image is with dd:

    # dd if=/dev/cdrom of=image.iso

The mkisofs command creates an ISO image in a file. The output file created by mkisofs can be written to CD-ROM or DVD-ROM with utilities such as cdrecord. The mkisofs command will create an ISO file from a directory containing all the files to be copied to the ISO file:

    $ mkisofs -V "Label" -o image.iso source_dir/ 

The -o option in the mkisofs command specifies the ISO file path. The source_dir is the path of the directory to be used as content for the ISO file and the -V option specifies the label to use for the ISO file.