dd command to create bootable iso image of hard disk

Question

Is it possible to use the dd command to create a bootable ISO image? I use the following command to do it:

dd if=/dev/sda of=/mnt/sdb/my.iso

I am able to create ISO, however I am not able to boot with it. When I try to boot, I get this error:

Operating System not found.

/dev/sda lists 4 partitions and in partition 1, grub is installed: filesystem is ext3.

Solution 1

filesystem is ext3

This says it all, as a CD has an ISO9660 file system, and dd won't convert one to the other.

Solution 2

You can't boot a HDD as a DVD or CD, due to different filesystems. You could possibly copy all the files with rsync and burn a DVD/CD with all the files, but you can't just dd a HDD image onto a DVD. You could use dd to copy one hard disk to another, and the second hard disk would be bootable, though.

On the other hand, you can try genisoimage (cdrkit, of the debian project) or mkisofs (cdrtools, which is what debian forked). I've used genisoimage to make bootable discs before, like when I copied all the files from a debian disc, changed a few, and remade a .ISO. It might not work for windows and some other OSes, but it's worth a shot.

I did my bootable CD following this page:
https://wiki.debian.org/DebianInstaller/Modify/CD

Comments

[Saqlain]

Well, I understand it, but my question is related to is there some way to create a bootable ISO image from hard disk on linux (i dont hv desktop environment like gnome or kde etc), or what are exact steps to create ISO image from an installed OS, so let say i can share it with someone else and he can just use that ISO or whatever format to create a system which is exact copy of what i got...

[Neil]

If your hard disk is small enough to fit on one CD then you might be able to use a live CD to give you enough Linux to restore the CD you created above to the new hard disk.

[Pacerier]

Then is it possible to boot the .ISO from VmWare/VirtualBox?