MIRROR IMAGE

The command line has many applications for burning data CDs or DVDs. But before you can actually burn a disk, you first need to create a so-called ISO image. ISO (or ISO 9660, to use the full name) is the standard filesystem for managing files on CDs.

mkisofs and dd are command line tools that help you create ISO images. The mkisofs utility supports the Rockridge and Joliet extensions (see the sidebar titled "Rockridge and Joliet"). You can even use mkisofs to automatically back up your data, excluding individual files if necessary. dd is an alternative tool that might be your last chance for rescuing data on a dying hard disk.