Open-source software CheckPoint and Restore in Userspace (CRIU) has released a new version that aims to preserve and restore processes in user space. The toolkit is designed to enable the maintenance of one or multiple processes and resume work from a saved position, even after rebooting the system or on an alternative server without interrupting existing network connections.
CRIU is a reliable tool that ensures the continuity of executing long-term processes. From the areas of application of CRIU technology, it is known to accelerate the launch of slow processes, allowing users to work with a state saved after initialization. It allows for the conducting of kernel updates without restarting a service or duplicating processes to another machine using the FORK method for the remote system.
The tool is used in container control systems such as OpenVZ, LXC/LXD, and Docker. The CRIU project code is available on GitHub. Changes necessary for the CRIU’s work are included in the primary composition of the Linux nucleus.
The new release provides non-root-level access to CRIU. It also supports the Sigtstp signal, which is an interactive suspension signal of execution that can be processed and ignored, unlike Sigstop. Moreover, the latest version allows for the skipping of file permission checks (R/W/X) when restoring.
CRIU also added the support of the IP_PKTINFO and IPV6_RECVPKTINFO options, and for ARM platforms, support for hardware points is implemented. It also optimized conservation points for highly sparse Ghost files (-Ghost-Fiemap).