Ubuntu 12.04 - How to Enable Hibernate
Ubuntu 12.04 doesn't have enabled hibernate feature by default, but you can enable it if your hardware has support for hibernation.
Before you turn on the hibernate option in Ubuntu 12.04 Precise Pangolin you need to be sure that you machine supports hibernate without any issues. Please consider that hibernate feature on unsupported devices could make a lot of problems even losing your data. You're warned!