Carlos,First a word of warning... your probably going to be getting a lot of nasty messages - cross posting to multiple lists like this, and sending a non-security related message to a security list is deeply frowned upon.
That said, I don't have a solution for you but I can provide some ideas on where to start looking.
One possible route would be to make a "Live CD" or DVD of the installation you like. You could boot from that. When you are done any changes would be discarded. Take a look at the Ubuntu live CD or the Knoppix Live CD for examples.
Another route would be to use something like LVM or XFS to do a snapshot of the current state of the OS, then save that to another partition or hard drive, and restore from it if needed.
If its just certain portions of the OS/Filesystem that your are concerned about and your not needing a backup solution, you could use ramdisks and the bind option of the mount command to mount ramdisks or even other disk partitions over the areas you want to "protect" - This is used by some live CD's and is what I use to reduce writes to flash media based systems.
If what you want is for instance a system for students or users that always returns to a default configuration, you could also do something like have a "default" image of what the system should look like stored in one partition, and then use the rsync command to syncronize the "live" version at shutdown or startup.
Finally, you might want to look at some sort of virtualization answer like VMware or Xen. I'm not extreamly well versed in it, but I think there is support for taking an image or snapshot of a virtualized system, and then loading it up as the image you want the virtual machine to run.
No promises that any of these ideas will take you anywhere or are even correct - this was all just an off the top of my head answer with no research behind it ;)
On Wed, 10 Dec 2008, Carlos Carrero Gutierrez wrote:
Hi, i would like to freeze my linux in order to freeze the OS, then, when I reboot the computer all changes that i made in the computer dissapears and it returns to the previous OS freezed. In windows there is something similar, called "Deep Freeze" (it's freeware). Somebody could help me? Thank you very much, I appreciate your help. -- To UNSUBSCRIBE, email to debian-security-REQUEST@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org