CRIU stands for Checkpoint/Restart in Userspace. As the criu package should be landing in Utopic soon, and I wanted to test drive it to see how it handles.
I thought of an interesting example of being in the middle of a linux kernel build and a security update needing to be installed and the machine rebooted. While most of us could probably just reboot and rebuild, why not checkpoint it and save the progress; then restore after the system update? I admit its not the most useful example; but it is pretty cool nonetheless.
sudo apt-get install criu
# start build; save the PID for later
cd linux; make clean; make defconfig
make & echo $! > ~/make.pid
# enter a clean directory that isn't tmp and dump state
mkdir ~/cr-build && cd $_
sudo criu dump --shell-job -t $(cat ~/make.pid)
# install and reboot machine
# restore your build
cd ~/cr-build
sudo criu restore --shell-job -t $(cat ~/make.pid)
And you’re building again!