The very first thing which is required to boot an ISO File On Linux is to have ubuntu as an operating system on your device. The another thing which is mandatory to have is the GRUB2 boot loader which must be used by your PC which is well known as the standard boot loader which is available on almost all the systems which are having Linux. But if you are thinking of getting an ISO file for Linux using Windows Boot Loader, then it is not possible and it cannot be done from Windows system.
Now you must be thinking that what is this GRUB2. So, GRUB2 is a boot loader by which you can directly boot your ISO files from your hard drive. You can also install Linux by partition or you can get the Boot Linux live CDs too. If you will choose to install Linux by partition, then you can do it without taking the risk of disc burning or booting from USB drive.
To Boot ISO File On Linux, if you have the Ubuntu version 14.04 then it is good. Then you can easily Boot ISO File On Linux.
Beginning the process, first thing you should do is Download the ISO files which you want to use and after downloading store it on your Linux partition which you have done. Keep in mind that your GRUB2 boot loader is supporting your Linux system. Another option for which you can go is Download the Live Cds version on your hard drive if you don’t want to install ISO File on your PC. Another important thing is the Linux based bootable utility discs should work properly on your system.
CHECK INSIDE THE ISO FILE
It is obvious that once you download any kind of file you will always look inside the file for checking that what does it contain. So, when you will Download ISO File On Linux you will definitely check which specific files it contains. Now after downloading ISO File if you want to open the “ISO FIle” in archeive manager then go in the “Nautilus File Manager” there you will be able to see the “Archieve Manager” , right click on the ISO file and you can open it with “Archieve Manager”.
After completing these process you have to locate the kernel file and initrd image. There is a casper folder in which you can find these things but you will find it only if you are using the Ubuntu ISO File.
As you can see in the above image, the initrd.lz is the initrd image file and the second one that is vmlinuz.efi is the kernel file. Both the files are available in the casper folder as mentioned above.
DETERMINING HARD DRIVE PARTITIONS PATH
You must be knowing that in the Linux System , there is path /dev/sda0 in which “a” represents the first hard disk and “0” represents the first partition. Now the same thing is there in GRUB (hd0,1) too, but it is opposite compared to Linux system, like in this /dev/sda0 “1” represents the first partition and “0” represents the first hard disk.
If you want to look at the information, you have to write a simple command in Ubuntu’s Terminal that is :
“ sudo fdisk -1”
When you will write this command, you will be able to see a list to Linux device paths and you can then convert the GRUB device name into the name which you want to keep.
CREATING GRUB2 BOOT ENTRY
If you want to create the GRUB2 boot entry, the best way for doing that is you have to do editing in the /etc/grub.d/40_custom script. This is basically made for custom boot entries. After doing this the contents which your ISO file contains will get combined via adding /etc/defaults/grub file and the /etc/grub.d/ and when these two paths will combina it will together create /boot/grub/grub.cfg file.
CODE TO BOOT ON UBUNTU FROM AN ISO FILE
By following these codings you can boot Ubuntu-based distributions directly from the ISO File.
The last thing which you can do is , if you want to add more Boot Options to the ISO file you can add additional sections to the file.
After completing the process save the file return to terminal and write the following command :