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Welcome to CRIU, a project to implement checkpoint/restore functionality for Linux in userspace.

Download Tarball: criu-4.2.tar.gz Version: 4.2 "CRIUTIBILITY" Released: 13 Nov 2025 GIT tag: v4.2 Installation • Usage Releases

CRIU is a sub-project of OpenVZ Linux Containers.

Latest version

Tarball:	criu-4.2.tar.gz
Version:	4.2 "CRIUTIBILITY"
Released:	13 Nov 2025
GIT tag:	v4.2

New features

• plugins/amdgpu: Implement parallel restore
• Handle processes with uprobes vma
• libcriu: Enable setting of RPC config file

Bugfixes

• criu/compel: fix compilation on musl/arm64
• pagemap: change PagemapEntry.nr_pages to uint64 to support huge mappings
• pagemap: prevent integer overflow in pagemap_len
• Relax ELF magic check to support MIPS libraries
• Fix: getsockopt usage for SO_PASSCRED/SO_PASSSEC on Linux 6.16

Improvements

• ci: consolidate aarch64 tests on GitHub runners
• cr-service: Refactor RPC config parsing
• Many improvements in pycriu

Old versions

4.x

The following 4.x releases were made:

• 4.1.1 "CRISCV"
• 4.1 "CRISCV"
• 4.0 "CRIUDA"

3.x

The following 3.x releases were made:

• 3.19 "Bronze Peacock"
• 3.18 "Silver Sandpiper"
• 3.17.1 "Radiant Redstart"
• 3.17 "Radiant Redstart"
• 3.16.1 "Petrified Puffin"
• 3.16 "Petrified Puffin"
• 3.15 "Titanium Falcon"
• 3.14 "Platinum Peacock"
• 3.13 "Silicon Willet"
• 3.12 "Ice Penguin"
• 3.11 "Glass Flamingo"
• 3.10 "Granite Eagle"
• 3.9 "Sand Martin"
• 3.8.1 "Snow Bunting"
• 3.8 "Snow Bunting"
• 3.7 "Vinyl Magpie"
• 3.6 "Alabaster Finch"
• 3.5 "Clay Jay"
• 3.4 "Cobalt Swan"
• 3.3 "Crystal Pelican"
• 3.2.1
• 3.2 "Tin Hoopoe"
• 3.1 "Graphene Swift"
• 3.0 "Basalt Wagtail"

2.x

The following 2.x releases were made:

• 2.12.1
• 2.12 "Vulcanite Rook"
• 2.11.1
• 2.11 "Acrylic Bullfinch"
• 2.10 "Brass Waxwing"
• 2.9 "Silk Tit"
• 2.8 "Bronze Siskin"
• 2.7 "Rubber Owl"
• 2.6 "Paper Crane"
• 2.5 "Concrete Oriole"
• 2.4 "Marble Lark"
• 2.3 "Wooden Duck"
• 2.2 "Carbon Nightingale"
• 2.1 "Steel Lapwing"
• 2.0

1.x

The following 1.x releases were made:

• 1.8
• 1.7.2
• 1.7
• 1.6.1
• 1.6
• 1.5.2
• 1.5.1
• 1.5
• 1.4
• 1.3.1
• 1.3
• 1.3-rc2
• 1.3-rc1
• 1.2
• 1.1
• 1.1-rc2
• 1.1-rc1
• 1.0

0.x

The following 0.x releases were made:

• 0.8
• 0.7
• 0.6
• 0.5
• 0.4
• 0.3
• 0.2
• 0.1

See also

• Changelogs to see all the changelogs on a single page.

Using

CR tools

Main checkpoint/restore utility description (sort of HOWTO)

Usage scenarios

Ideas how crtools can be used (some are crazy indeed)

What software is supported

Describes TODO list in higher level terms

LXC

How to dump and restore an LXC container

Developing

If you're interested in CRIU development, subscribe to the criu mailing list: https://openvz.org/mailman/listinfo/criu

Images

Description of image files format

Commits

Mainline kernel commits tracker

ZDTM Test Suite

Zero downtime test suite

TODO

Current TODO list

Under the hood

• Sockets
• Memory dumping and restoring
• Checkpoint/Restore
• TCP connection
• Porting crtools to new kernel releases
• Files

External links

• 2025-11-17, Engine-Agnostic Model Hot-Swapping for Cost-Effective LLM Inference
• 2025-08-13, Software Availability Protection in Cyber-Physical Systems
• 2025-07-14, PhoenixOS: Concurrent OS-level GPU Checkpoint and Restore with Validated Speculation
• 2025-06-18, Improving Checkpoint/Restore Functionality in Kubernetes
• 2025-06-17, LWN.net: A parallel path for GPU restore in CRIU
• 2025-06-13, Kubernetes Scheduling with Checkpoint/Restore: Challenges and Open Problems

More external articles...