====== Ubuntu - ISO - Create ISO from a Bootable USB Drive - Using mkisofs ======

**mkisofs** creates ISO 9660 file system images, typically for generating CD and DVD images.

----

===== Convert to ISO File =====

First, let’s install mkisofs:
<code bash>
sudo apt install mkisofs
</code>

----

Create a mount point:

<code bash>
mkdir /mnt/usb_drive
</code>

----

===== Mount the USB drive =====

<code bash>
sudo mount /dev/sdb1 /mnt/usb_drive
</code>

----

===== Create the ISO image from the mounted directory =====

<code bash>
sudo mkisofs -o myisofile.iso -R -J -input-charset utf-8 /mnt/usb_drive/
</code>

returns:

<code bash>
Total translation table size: 0
Total rockridge attributes bytes: 3852
Total directory bytes: 123456
Path table size(bytes): 141
Max brk space used 26000
1312794 extents written (999 MB)
</code>

<WRAP info>
**NOTE:**

  * **-o**: specifies the name of the output ISO image file.
  * **-R**: generates the Rock Ridge extension for UNIX file attributes.
  * **-J**: generates the Joliet extension for Windows file systems.
  * **-input-charset utf-8** the character encoding to be used when creating the ISO image.

</WRAP>

----

===== Verify the ISO file =====


<code bash>
isoinfo -d -i myisofile.iso
</code>

returns:

<code>
CD-ROM is in ISO 9660 format
System id: LINUX
Volume id: CDROM
... 
Volume set size is: 1
Volume set sequence number is: 1
Logical block size is: 2048
Volume size is: 123456
Joliet with UCS level 3 found
Rock Ridge signatures version 1 found
</code>

<WRAP info>
**NOTE:**  The resulting output confirms that the myisofile.iso file is in the ISO 9660 format.
</WRAP>