The ISO 9660 standard was developed over 20 years ago. It is the official standard for CD-ROM. A physical CD conforming to the standard can be read by any CD-ROM drive in any OS and if it happens to be a music CD, it will play in any CD player. The file extension “.iso” indicates an image file conforming to the standard. This image, when burned to a CD will result in a physical CD conforming to the standard. This is incredibly handy. These .iso files can be shared via the internet. A CD holds about 700MB of data. A 1 GB USB flash drive will easily hold an 700 MB image and a larger flash drive can hold more. Furthermore, if a software utility is used to mount the image it is often not necessary to burn the image to a physical CD. In previous articles I discussed using Knoppix and Puppy Linux booted from flash drives instead of CD’s.
Windows does not provide support for the .iso format out of the box. Microsoft does provide a free “power toy” that will add some support. Other than that, Windows users have a little freeware and a lot of shareware to handle .iso files. A freeware called MagicDisc will allow the mounting of images and another called ImgBurn will burn iso images to CD’s. Follow the links, download the installers from the home pages and you should have enough software to handle most of your iso needs. Stay away from shareware that “bastardizes” the format. Nero will create .nrg files and Power ISO will create .daa files. They will do little for you and will cost you a few dollars for legal use.
Linux, on the other hand, has built-in support. Users who insist on a graphical tool should consider AcetoneISO2, a very versatile toolbox that will handle every iso related task that you may ever encounter. On the other hand there are a few simple command line tools to handle basic iso tasks.
Mounting An Image
1. Open a terminal window.
2. Create a mount point for the image.
sudo mkdir media/iso
This directory can be deleted later, but since you are likely to use it again you may as well leave it.
3. Issue the mount command.
sudo mount -o loop /path/to/myiso.iso /media/iso
The .iso file is now mounted. If you’re using Ubuntu it will appear in the Places menu. It will also appear on the File Systems tab of the System Monitor. If it is a music CD image you can play it. If it is data you can edit it. Have fun!
4. When you are done with the file you should unmount it.
sudo umount /media/iso/
Create an iso image of a CD
1. Insert the CD. Linux will mount the CD. You can see it in the System Monitor if you like.
2. Unmount the device and create the iso.
sudo umount /dev/cdrom dd if=/dev/cdrom of=myiso.iso bs=1024
Create an ISO From a Folder
mkisofs -r -o myiso.iso /path/to/myfolder/
ISO files enable CD sharing via the internet. In many cases the actual creation of a physical CD can be avoided. Linux supports the format natively but free tools are also available to Windows users so that basic iso operations are accomplished easily in either operating system.