CDs and DVDs don't have the eternal life, so you might want to back them up as ISO images. All the files and properties of the original disc, stored in a single file. You can also create ISO images and store them on your network for easy distribution of software installations. Here's how to create and mount ISO images on Linux.

Graphical utilities

Of course you can always install and use graphical disc authoring software like GnomeBaker or K3b, but that's outside the scope of this this article. I just want to show you how you can quickly create an ISO image without installing additional software.

Command line

We're going to use the command line tool dd tool for this. Insert the disc that you want to copy and open a terminal.

Create a cdrom image

Now in the terminal type:

sudo dd if=/dev/cdrom of=cd.iso

A little explanation

• sudo makes sure the command is executed as root. That's needed only if the user you're working under doesn't have enough permissions to access the device. But it's ignored if it's not needed so you can just ignore it as well.
• dd stands for Disk Dump
• if stands for Input File
• of stands for Output File

Wait for the command to finish, and your new iso will be saved to cd.iso. Like this:

Create a dvd image

For a DVD image, your device is probably called /dev/dvd instead of /dev/cdrom so the command would look like this:

sudo dd if=/dev/dvd of=dvd.iso

Create a scsi cdrom image

For a SCSI CDROM image, your device is probably called /dev/scd0 instead of /dev/cdrom so the command would look like this:

sudo dd if=/dev/scd0 of=cd.iso

Mounting an image

Once you've created an ISO image you can mount it as if it was a normal disc device (loopback) device. This will give you access to the files in the ISO without you having to burn it to a disc first. For example if you wanted to mount cd.iso to /mnt/isoimage you would run the following commands:

mkdir -p /mnt/isoimage
mount -o loop -t iso9660 cd.iso /mnt/isoimage

Unmounting

To unmount a currently mounted volume, type:

umount -lf /mnt/isoimage

/mnt/isoimage is the location of your mounted volume.