AWS and Canonical today announce the public release of Amazon EC2 Hibernation support for Ubuntu 18.04 LTS, as part of the efforts to continuously optimise Ubuntu on AWS.
Amazon EC2 Hibernation gives you the ability to launch Amazon 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. Using hibernate, you can maintain a fleet of pre-warmed instances that can get to a productive state faster, and you can do this without modifying your existing applications.
The necessary software updates are available in Ubuntu 18.04 LTS AWS Machine Images (AMIs) with a serial of 20190722.1 or later. Support for other Ubuntu releases is in progress.
Once you've learned about Amazon EC2 hibernation, you can enable hibernation for your Amazon EC2 instances using the Amazon EC2 Hibernation user guide.
There is a known issue when using Amazon EC2 Hibernation related to KASLR (Kernel Address Space Layout Randomisation). KASLR is a standard Linux kernel security feature which helps to mitigate exposure to and ramifications of yet-undiscovered memory access vulnerabilities by randomising the base address value of the kernel. In a small percentage of tests, instances with KASLR enabled do not resume and become completely unusable after hibernation. Disabling KASLR, which is enabled by default, is known to avoid this issue. Please see bug lp:1837469 for additional details.