Welcome to CRIU, a project to implement checkpoint/restore functionality for Linux.
Checkpoint/Restore In Userspace, or CRIU (pronounced kree-oo, IPA: /krɪʊ/, Russian: криу), is a Linux software. It can freeze a running application (or part of it) and checkpoint its state to disk. The data saved can be used to restore the application and run it exactly as it was during the time of the freeze. Using this functionality, application or container live migration, snapshots, remote debugging, and many other things are now possible.
CRIU started as a project of Virtuozzo, and grew with the tremendous help from the community. It is currently used by (integrated into) OpenVZ, LXC/LXD, Docker, Podman, and other software, and packaged for many Linux distributions.
- Usage scenarios
- Ideas how criu can be used (some are crazy indeed)
- Collection of real world examples of how to use CRIU. Some are complex, some are not. HOW TO dump a simple loop might be the best one to start with. Also a set of asciinema records for real-life examples.
- What can change after C/R
- CRIU cannot (yet) save and restore every single bit of tasks' state. This page describes what bits visible through standard kernel API are such.
- What cannot be checkpointed
- What an application could do to make CRIU refuse to dump it.
- Ways to communicate with CRIU community
If you're interested in CRIU development, please subscribe to the criu mailing list: https://lists.openvz.org/mailman/listinfo/criu
- Description of image files format
- CRIU can call plugins provided by people
- Upstream kernel commits
- Mainline kernel commits tracker
- Recent commits
- CRIU tool repository commits
- Kernel's manpages commits tracker
- ZDTM Test Suite
- Zero downtime test suite
- Current TODO list
- User namespace
- Implementing user namespace support
- What to keep in mind when writing new code
- Code coverage results
- Shows how zdtm run covers the criu code paths
Under the hood
- 2019-10-03, Fast In-Memory CRIU for Docker Containers
- 2019-09-11, Performance Estimation of Container-BasedCloud-to-Fog Offloading
- 2019-07-16, FastContainer: A Homeostatic System Architecture High-speed Adapting Execution Environment Changes
- 2019-07-11, Exploring Potential for Non-Disruptive Vertical Auto Scaling and Resource Estimation in Kubernetes
- 2019-07, University of Twente: Increasing Availability of the AEPU by Improving the Update Process
- 2019-05-25, Replayable Execution Optimized for Page Sharing for a Managed Runtime Environment
- 2019-04-29, Binghamton University: mWarp: Accelerating Intra-Host Live Container Migration via Memory Warping
- 2019-04-10, CRIU and SELinux
- 2019-03-27, Container Migration in the Fog: A Performance Evaluation
- 2019-03-25, Checkpointing and Migration of IoT Edge Functions
- 2019-03-24, Future University Hakodate: Yet Another Container Migration on FreeBSD
- 2019-03-09, Provenance-based fault tolerance technique recommendation for cloud-based scientific workflows: a practical approach