Need VM to discard any changes to the disk on next boot

[mcunicode]

Hi,

I am setting up a "public" gaming stations for the staffs. As a lot of staffs maybe making changes to the system, downloading files, i would need these changes to be discarded on the next boot. The system will always boot into the original image when it were first installed.

Of course, only authorised admin could can make changes to the system.

I found a software called Reboot and Restore, however, the normal user could see it and they could turn it off.

Is there a way that we could do it at the proxmox host layer?

 

[spirit]

do a snapshot, rollback to snapshot.

or create a new vm with a linked clone from a template, and destroy the vm.

 

[Dunuin]

Maybe creating a cloned VM and destroying it after use?
https://pve.proxmox.com/wiki/VM_Templates_and_Clones

 

[leesteken]

I keep one VM regularly up to date and create a full clone (slow) that is turned into a template (which cannot be changed) with a self-destruct hookscript. Each time I need a disposable VM, I create a linked clone from the template (very fast) and start it. They are all removed upon shutdown automatically.

 

[glennswest]

Is there a way of setting a action on shutdown? So the "clone" can delete itself, and reclone?

 

[leesteken]

Is there a way of setting a action on shutdown? So the "clone" can delete itself, and reclone?

You can do that with a hookscript. Several examples (in bash and perl) on this forum.

 

[glennswest]

Looks like a hookscript will do it.
https://forum.proxmox.com/threads/script-to-execute-after-vm-is-shutdown.121797/
So on shutdown, delete linked clone, and clone(Linked clone) from template.

 

[glennswest]

You can do that with a hookscript. Several examples (in bash and perl) on this forum.

Thanks - exactly what I need.

 

[mcunicode]

Is there a way of setting a action on shutdown? So the "clone" can delete itself, and reclone?

I have found an easier way. In the disk that you want to discard, set the snapshot option. It will discard once it is shutdown and start again (not reboot though )

 

[glennswest]

That is fine. No script needed.
If you reboot, be nice, because someone will "think" there change is persisted, when in reality its not.

 

[LnxBil]

With QEMU/KVM, you can create immutable disk images that have all changes in a temporary layer that gets discarded after the VM is powered down. The parameter -snapshot should do just that.