Easy rollback for client computers

[Remo84]

Hi everyone,

I work for a university and we have many client computers for our students. The computers are running Debian. We are looking for a fast rollback mechanism so that we can "clean" the computers after a lesson. It should be possible to rollback all the changes the students made in no time.
For our Windows clients we boot a VHD with an overlay filesystem. So all the changes are made in this overlay. To rollback we reboot the computer and select another boot menu. After that WinPE boots up and deletes the overlay to create a new one. After another reboot the system comes up clean.
I am wondering if there is a similar approach for Debian. I know that a qcow2 image can use a backing file as overlay. So the question is, does GRUB support booting a qcow2 image? Or maybe someone knows a better solution for our problem?

Thank you
Remo

[dasein]

There are lots of different ways to achieve your stated goal.

But prior to exploring those options, I find myself questioning your premise: why would you want to obliterate students' work? Is there absolutely no carry-over between lessons? Do you never assign homework based on a particular lesson?

Without knowing details, it seems to me that a separate working area for each student is a much more pedagogically useful option.

[Remo84]

Thank you for your reply,

You are absolutely right that students work is important. Let me explain it in a bit more detail. We teach computer networking basics and our students get a PDF (lab guide) with all the information they need. For example a documentation of the topology. In the lab guide we ask questions and the students have to explore that by testing. All the answers have to be documented by the students so their work is not lost after the laboratory.
After the exercise we have to get rid of all the configurations which the students have done so that we get a clean environment for the next group.
I hope I could make it more understandable why we need a rollback.

Thanks
Remo

[dasein]

I hope I could make it more understandable why we need a rollback.

Frankly, no. All you did was articulate a compelling reason why each student's work needs to be segregated and protected from other students' work. That's easily accomplished by giving each student his/her own /home directory in which to work.

Sorry if I'm being dense. But I'm still not "getting it."

[Remo84]

During the exercise the students have to install some packages and do configurations on the Debian. Because the next group has to do the same exercise, we have to undo all the changes from the previous group. To do so manually would be very time consuming so I am looking for a faster solution. As I mentioned, on Windows we boot a VHD with an overlay filesystem. All the changes are made in this overlay. To do a rollback, we only have to delete the overlay. This takes only a minute.
I am looking for a similar solution on Debian. Is there any?

Thanks
Remo

[orythem27]

• aufs
• OverlayFS
• Persistent Live Image with casper-rw filesystem
• Virtualization
• Filesystem-based rollback
• drbl
• ...