The EC2 Hibernation feature is now available in the AWS GovCloud (US) Regions. Hibernation gives you the ability to launch EC2 instances, set them up as desired, hibernate them, and then quickly bring them back to life when you need them. Applications pick up exactly where they left off instead of rebuilding their memory footprint. By using Hibernation, you can maintain a fleet of pre-warmed instances to get to a productive state faster without modifying your existing applications.
Source:: Amazon AWS