criu is an utility to checkpoint/restore a process tree. It's already available in some distributions in form of packages. This page describes manual installation.
Tools installation
Get the latest release:
| Tarball: | criu-4.0.tar.gz |
| Version: | 4.0 "CRIUDA" |
| Released: | 20 Sep 2024 |
| GIT tag: | v4.0 |
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.