It happened that I had set the grub password in grub.conf. But, using a live linux iso, I was able to delete the password from the grub.conf. Please read the steps for the same mentioned in this link: http://gofedora.com/how-to-recover-crack-root-password-grub-locked/
Instead of editing menu.lst, I edited the grub.conf. Rest all steps same
My question is: Is there a way to prevent such a hack. When I tried rescuing, the system showed a message that if it is not able to rescue (i.e. if it fails mounting the HDD under the directory: /mnt/sysimage), do I want to continue/skip/abort.
So, I feel that there must be a concrete way of preventing such hacks by doing something with the mounts/boot etc, which shall prevent mounting into /mnt/sysimage.
Any help would be valuable
PS: Please re-consider this environment for a virtualised environment where the actual VM in VSphere is a linux VM, and I need to disable/delete the CD/DVD-Rom and network boot from BIOS. After doing all that stuff, I want to re-package the VM into .ovf and check whether the new ovf has the BIOS restrictions or not.