ISO IMAGE FILES

What are ISO image files?
An ISO image is an archive file (also known as a disk image) of an optical disc in a format defined by the International Organization for Standardization (ISO). ISO image files typically have a file extension of .iso. The name ISO is taken from the ISO 9660 file system used with CD-ROM media according to wikipedia.org.

So these are the basic points i am going to cover in this post

  • How to create an iso file?
  • How to mount an iso file?
  • How to unmount an iso file?
  • How to update an iso file?
  • How to write an ISO file to CD?
  • How to view content of iso file?

1)How to create an ISO image?
As of now I know two methods to create an ISO file. One is through dd command(disk dump) and other is mkisofs command

A)Creating ISO files from cd-rom/dvd by using dd command

#dd if=/dev/cdrom of=/temp/songs.iso
dd if=/dev/dvd of=/temp/songs1.iso # for dvd
dd if=/dev/scd0 of=/temp/songs2.iso # if cdrom is scsi

Let me explain what actually the above command will do. dd is a disk dump command which will present in most of the Linux/nix systems and “if” specifies input file and “of” specifies output file. So we are specifying to dd command what is our input file and where is our output file.
Here my songs.iso file is created in /temp folder.

B)Creating ISO file using mkisofs command.
Method1:Creating an iso image from cd-rom

#mkisofs /dev/cdrom -o /temp/songs3.iso

Method2:Creating an iso image from a folder

Suppose i am having a folder /opt/data which contains some data to be converted in to .iso file, follow below step

#mkisofs -o /temp/songs4.iso /opt/data

2)How to mount an ISO file?
#mount -o loop /temp/songs4.iso /opt/mountpoint

3)How to unmount an ISO file?
#umount -lf /opt/mountpoint

here /opt/mountpoint is the place where my iso file is mounted.