Q: Your team wants to implement live migration of a running Docker container from one host to another without stopping it, similar to VM live migration. Is this possible with Docker? What technology enables it?
Docker has experimental support for checkpoint and restore using CRIU (Checkpoint/Restore In Userspace). CRIU freezes a running process, ...
🛠️ Production Runbook & Step-by-Step Resolution
Initial Diagnostics & Root Cause Analysis
Docker has experimental support for checkpoint and restore using CRIU (Checkpoint/Restore In Userspace). CRIU freezes a running process, serializes its entire state (memory, registers, open files, sockets, timers) to disk, and can restore it later — even on a different host.
- Checkpoint:
docker checkpoint createcheckpoint1 - Transfer the checkpoint data and container filesystem to the target host.
- Restore:
docker start --checkpoint checkpoint1
Remediation & Permanent Safeguards
Workflow: *Limitations:* This feature is experimental and not production-ready. Open network connections break (TCP state doesn't survive cross-host migration). External storage must be shared (e.g., NFS). GPU state, complex IPC, and certain kernel features aren't fully supported. For production workloads, Kubernetes pod rescheduling with graceful shutdown/startup is the practical alternative.
- Checkpoint: docker checkpoint create checkpoint1
- Transfer the checkpoint data and container filesystem to the target host.
- Restore: docker start --checkpoint checkpoint1