I would like to fully understand how virtual machine snapshots work. Although I have researched this subject I cannot seem to find a "high-level" overview of how snapshots work practically. My questions are:
Example scenario: I have an Ubuntu 12.04 host running KVM with an Ubuntu guest. The virtual machine is in the RAW format. I snapshot it using
- Is the resulting file (the snapshot) bootable? Or is simply change data that requires the base image to be usable ?
- How does one roll back to a prior state ?
- Does having a lengthy snapshot chain degrade performance of the virtual machine? If so, why ?
- How does one manage / prune snapshots?