Hi greetings, My name is teckno I'm learning Linux, i would appreciate any help possible, thanks in advance.

Here is my problem:

I need to Modify the grub boot option adding a start option on devian (i have 2, the original and the recovery one).

Hi tecknovikingo

If you are using grub2 this page should help
https://help.ubuntu.com/community/Grub2
http://www.dedoimedo.com/computers/grub-2.html

anything like "the stig"

what OS is this ?
and what version of GRUB ?
the legacy 0.9 or the current 2

adding a couch ( 3 person or two person"love seat" ) will be fun

but if you are referring to "Debian"
the instructions will be VERY different for the legacy grub or the current grub2

Hey thanks for commenting guys, i really appreciate it.
i'm searching for the way to add a new start option in the menu of the grub loader, where the users choose the system that they want to use. up to now i have 2 start options, the regular one (devian os) and the recovery one (devian too), what im searching for is to add one new start option of devian (a copy of the original) to practice. i know that this can be created editing the grub.cfg file but no more. if you know the way to make it, please share your response with me, thanks.

again
what operating system are you using and what version

the version of the OS will help us to know WHAT VERSION OF GRUB you are using
the instructions for grub 2 are VERY VERY DIFFERENT than the instructions for grub legacy

The recovery console is usually not meant for users.
Did you perhaps mean Debian?

Do you have more than 1 Linux installation that you'd like to present to your users from a grub menu?

Please clarify.
Thank you.

If I understand correctly, you want to use Grub to start a "copy" of the installed Debian OS for practice in such a way that, if you break it, it won't affect the existing install.

That would be asking Grub to do something it's not designed to do. It can't boot a copy of an installed OS into a sandbox of some sort. You can created a second pointer to the existing Debian install, but it will still boot the existing OS, not a sandboxed copy of some sort.

If you have enough RAMs, the best way to set up something for practice is to create a Virtual Machine using VirtualBox or some other virtualizer. That way, if you break the VM, you can simply delete it and start over.

Alternatively, you make your computer dual-boot by installing a second OS, but a VM would be the best way to go.