Installation

criu is an utility to checkpoint/restore a process tree.

Tools installation

Get the latest release:

Tarball:	criu-3.19.tar.gz
Version:	3.19 "Bronze Peacock"
Released:	27 Nov 2023
GIT tag:	v3.19

Alternatively, use git.criu.org git repository. Clone this repo to test new functionality.

Before building, make sure you have C bindings for Google's Protocol Buffers installed. In an RPM-based world this is the protobuf-c-devel package, and on Debian and derivatives, libprotobuf-c0-dev. If for some reason there is no appropriate package for your system available, just install Google's Protocol Buffer from the source tarball. The protocol buffer library can be found at http://code.google.com/p/protobuf/, while protocol buffer C binding can be found at http://code.google.com/p/protobuf-c/.

Then run make in the sources root. Please note that the tool only supports x86_64 and ARM architectures.

Kernel configuration

Linux kernel v3.11 or newer is required, with some specific options set. If your distribution does not provide needed kernel, you might want to compile one yourself. Note we also have our custom kernel, which might contain some experimental CRIU related patches.

Note you might have to enable

CONFIG_EXPERT

General setup -> Configure standard kernel features (expert users)

option, which depends on

CONFIG_EMBEDDED

General setup -> Embedded system

(welcome to Kconfig reverse chains hell).

The following options should be enabled for CRIU to work:

CONFIG_CHECKPOINT_RESTORE

General setup -> Checkpoint/restore support

CONFIG_NAMESPACES

General setup -> Namespaces support

CONFIG_PID_NS

General setup -> Namespaces support -> PID namespaces

CONFIG_FHANDLE

General setup -> open by fhandle syscalls

CONFIG_EVENTFD

General setup -> Enable eventfd() system call

CONFIG_EPOLL

General setup -> Enable eventpoll support

CONFIG_INOTIFY_USER

File systems -> Inotify support for userspace

CONFIG_IA32_EMULATION

Executable file formats -> Emulations -> IA32 Emulation

CONFIG_UNIX_DIAG

Networking support -> Networking options -> Unix domain sockets -> UNIX: socket monitoring interface

CONFIG_INET_DIAG

Networking support -> Networking options -> TCP/IP networking -> INET: socket monitoring interface

CONFIG_INET_UDP_DIAG

Networking support -> Networking options -> TCP/IP networking -> INET: socket monitoring interface -> UDP: socket monitoring interface

CONFIG_PACKET_DIAG

Networking support -> Networking options -> Packet socket -> Packet: sockets monitoring interface

CONFIG_NETLINK_DIAG

Networking support -> Networking options -> Netlink socket -> Netlink: sockets monitoring interface

For some usage scenarios there is an ability to track memory changes and produce incremental dumps. Need to enable

CONFIG_MEM_SOFT_DIRTY

Processor type and features -> Track memory changes

iproute2

The iproute2 tool version 3.5.0 or higher is needed for dumping network namespaces. The latest one can be cloned from iproute2. It should be compiled and a path to ip written in the environment variable CR_IP_TOOL.

Checking how it works

First thing to do is to run

# criu check --ms

At the end it should say "Looks OK", if it doesn't the messages on the screen explain what functionality is missing. If you're using our custom kernel, then the --ms option should not be used, in this case CRIU would check for all the kernel features to work.

You can then try running the ZDTM Test Suite which sits in the tests/zdtm/ directory.

There's a known issue with BTRFS spoiling dev_t values for files and sockets! Not all tests will work on it.

Using CR tools

Please see Usage and Advanced usage, as well as Category:HOWTO.