EC2 Hibernate Feature

Overview

EC2 Hibernate is a feature that allows you to preserve the in-memory (RAM) state of your EC2 instance, enabling faster boot times upon restart.

Key Points

• Data Preservation: When an EC2 instance is hibernated, the RAM content is saved to the root EBS volume.
• Faster Boot: The operating system is not stopped or restarted but is frozen, which allows for a much quicker boot time.
• EBS Requirements: The root EBS volume must be encrypted and have enough space to store the RAM content.
• State Restoration: Upon restart, the RAM content is loaded from the EBS volume back into the instance's memory as if it never stopped.

How it Works

1. An EC2 instance is running with data in RAM.
2. Initiate hibernation; the instance enters the 'stopping' state.
3. RAM is dumped to the root EBS volume.
4. The instance is shut down, and RAM is cleared.
5. Upon starting the instance, RAM is loaded from the EBS volume to memory.

Use Cases

• Long-Running Processes: Keep processes running without actual stoppage.
• RAM State Preservation: Save the RAM state for various reasons.
• Fast Boot: Quickly boot instances with services that have lengthy initialization times.

Considerations

• Instance Families: Supports various families, but not bare metal instances.