Firecracker 1.2: Resilient MicroVMs for Edge and CI

Introduction

On September 22, 2020, AWS advanced the lightweight virtualization project with Firecracker 1.2.0. Snapshot diffing, improved resource controls, and CPU templates make microVM fleets easier to manage for serverless, CI, and edge workloads.

Snapshot Diffing & Restore Enhancements

• Incremental snapshots let operators persist deltas instead of full memory images, shrinking storage consumption and speeding rollbacks.
• REST APIs expose snapshot lineage, enabling GitOps-style infrastructure management.
• Snapshot validation hooks ensure images match expected kernel and rootfs metadata before launch.

Resource Isolation Upgrades

1. cgroup v2 support aligns Firecracker with modern Linux distributions and systemd defaults.
2. CPU templates (T2, C3, custom) optimize microVM performance for workloads ranging from compute bursts to steady web traffic.
3. I/O rate limiter improvements provide smoother throttling for noisy tenants.

Operational Tooling

• firectl CLI updates add YAML configuration and multi-VM orchestration helpers.
• Cloud-init integration simplifies VM preparation, injecting SSH keys and user data without custom images.
• Enhanced logging delivers structured events suitable for ELK or CloudWatch ingestion.

Getting Started

curl -LO https://github.com/firecracker-microvm/firecracker/releases/download/v1.2.0/firecracker-v1.2.0
chmod +x firecracker-v1.2.0

Create incremental snapshots:

./firecracker-v1.2.0 --api-sock /tmp/firecracker.socket
# create base snapshot via API
# resume workload and capture diff snapshot

Summary

Firecracker 1.2 equips platform teams with the tooling needed to run secure, high-density compute across serverless, CI, and edge scenarios.