2 Ways to Create an ISO Image File in Linux

An ISO image file is an archive of files and directories compressed using the ISO 9660 format. It is suitable for writing CD or DVD discs, sector by sector.

When you download an operating system or even some games, they give you their ISO image file. Either you can uncompress/mount them on your system or burn a CD/DVD disc using the ISO image file.

However, we have already written a detailed guide on how to mount and unmount an ISO image on Linux. Therefore, today’s focus will be on creating an ISO image file from a collection of files or media devices in Linux.

How to Create an ISO Image File in Linux

In Linux, you will get two commands to create an ISO image file: dd (abbreviation of Data Definition) and the mkisofs command.

Does dd create an ISO image? The dd command is commonly used for copying or converting files. However, you can use the same command to create an ISO image from a media device connected to your system, like CD/DVD discs.

What are mkisofs used for? It is used to create an ISO image file from a bunch of files located in your system for writing to CDs or DVDs.

Prerequisite

First, you need to insert the media devices like CDs or DVDs and find the full path to these devices using the df command.

[email protected]:~$ df
Filesystem     1K-blocks     Used Available Use% Mounted on
tmpfs             810756     2028    808728   1% /run
/dev/sda3      102106072 10405360  86467868  11% /
tmpfs            4053768        0   4053768   0% /dev/shm
tmpfs               5120        4      5116   1% /run/lock
/dev/sda2         524252     5364    518888   2% /boot/efi
tmpfs             810752      116    810636   1% /run/user/1001
/dev/sdb1 iso9660 2.2G 2.2G 0 100% /media/trendoceans/Ubuntu       <== DVD Media

However, if you want to create an ISO image file from a group of files and directories stored on your machine, find the path to that directory using the pwd command.

The GNU/Linux pwd command is used for finding the full path of a directory with a bunch of files
The GNU/Linux pwd command is used for finding the full path of a directory with a bunch of files

Once you have the location of the file, you can continue to perform any of the below steps to create an ISO image file from a bunch of files or directories in Linux.

Using the dd command

The dd command is a utility for Linux systems that provides you with features like converting and copying files from two different sources. 

On the Linux system, hardware devices or special device files (like /dev/zero and /dev/random) are usually mapped as system files.

The dd command has the capability to read or write these files and perform tasks such as backing up the boot sector of a hard drive.

It can also perform conversions on the data as it is copied, including byte order swapping and conversion to and from the ASCII and EBCDIC text encodings.

The same command can easily create an ISO image file from the inserted disc on your machine. Just use the following command and do not forget to replace the mount location with your own.

$ sudo dd if=/dev/sdb1 of=/home/trendoceans/Documents/ubuntu.iso

Whereas,

  • if requires the mount location of the media devices (CD or DVD) instead of stdin.
  • of requires the location to save the ISO image file instead of stdout.

Using the mkisofs command

The mkisofs command is used to create an ISO file from a directory containing a bunch of files that can be used to burn CDs or DVDs later.

For example, you have a directory located at /home/trendoceans/mydir/ which contains a lot of files, and you want to create an ISO image file of that directory.

For that, you can use the mkisofs command with the -o option, specifying the location to save the ISO file and the path of the directory containing the bunch of files, as shown below.

$ mkisofs -o ~/image.iso /home/trendoceans/mydir/
$ ls -lah image.iso

Below is the output of the above command.

Creating an ISO Image File from a Collection of Files in Linux Using the mkisofs Command
Creating an ISO Image File from a Collection of Files in Linux Using the mkisofs Command

These are the two methods used to create an ISO image file from the command line. However, if you have any queries regarding the topic, feel free to comment.

Leave a Reply