How can I check that the ISO image I've downloaded is bootable, before I burn it?
isoinfo can probably tell you if it has the right files to boot if you want quick and dirty.
isoinfo -l -i is_it_bootable.iso will list the directory structure so you can check for files a live cd / bootable cd should have.
isoinfo -d -i is_it_bootable.iso will tell you if the CD has an El Torito section. Ubuntu's live CD iso reports:
Eltorito validation header: Hid 1 Arch 0 (x86) ID '' Key 55 AA Eltorito defaultboot header: Bootid 88 (bootable) Boot media 0 (No Emulation Boot) Load segment 0 Sys type 0 Nsect 4 Bootoff 8F 143
Performing a cryptographic hash verification of the ISO file you downloaded consists of the following steps.
Open a terminal and type the following:
Note: there's a space after the
Now open Nautilus and browse to the folder containing the ISO file.
- Drag the ISO file to the open terminal window. This will insert the path / filename of the ISO file into the terminal window.
- Press Enter in the terminal window.
- The first part of the output is the MD5 hash of the CD.
- Go here and find the directory that corresponds to your release and find the file
MD5SUMS. Compare the hash of your ISO file to the appropriate entry in that file.
If the two hashes do not match, then your ISO file is corrupt and you will need to download it again.
If you have a good-enough CPU, install VirtualBOX, and setup some Virtual Machine. Make it point to the ISO as the CDROM, and configure it to first boot from CDROM. It willboot from the ISO file directly, without actually having to burn the file.
Another thing that I always do, as a general practice, is to actually put the ISO on a USB key and boot from it, which is something now possible with most computers. UNETBOOTIN (just google it) will do this for you. Just expect the USB disk to be completely wiped.
I now never boot from a CDROM anymore. I can't remember the last time I actually burned a CDROM.
A superficial way is to run
file. In the end of the line it prints whether iso is bootable, e.g.
$ file fd11src.iso fd11src.iso: ISO 9660 CD-ROM filesystem data 'FD11SRC' (bootable)
A more profound way is to use an emulator like qemu:
qemu-system-x86_64 -boot d -cdrom image.iso -m 512
If it loads, then everything is fine. Despite the complete emulation, to run it is very easy and not resource-consuming.
These methods should work for any Linux distribution.
It's very simple. We will go step by step...
- By using PowerISO.
- First download and install PowerISO.
- Open PowerISO.
- Then click on FILE and then on OPEN and browse and open the ISO file.
- When you have opened that ISO file if that file is bootable then in the lower left end, it shows "Bootable image". If not a bootable image, then it shows "Nonbootable image".