saverestore

Saverestore refers to the process of saving the complete state of a computing system, software process, or virtualized environment to persistent storage and later restoring it to resume execution from the same point. A saverestore operation typically captures memory contents, CPU state (registers, program counter), and the state of devices, I/O queues, and open resources. The goal is to enable seamless continuation after a pause, crash, or migration, while preserving the exact progress and context of execution.

Common applications include emulation and gaming, where save states capture the entire emulated system so players can resume at any moment; virtualization and container environments, where checkpointing and restore enable live migration, fault tolerance, and fast startup; and high-performance computing, where periodic checkpoints provide resilience against node failures during long-running computations. Saverestore is also used in debugging and reproducibility workflows to record and later reproduce complex execution paths.

Techniques for saverestore involve serializing and exporting the program’s or system’s state, including memory, processor state, and peripheral configurations. Considerations include ensuring consistency across devices, handling non-deterministic data, and deciding between full versus incremental checkpoints. Timing and performance overhead, as well as compatibility across software versions and hardware, are important design factors.

Notable tools and implementations span various domains. In Linux, CRIU provides checkpoint/restore for user-space processes; DMTCP supports distributed checkpointing; virtualization platforms implement snapshotting and migration features; game engines and emulators commonly offer save-state functionality. Security and privacy concerns arise when checkpoints persist sensitive data.

See also: save state, checkpointing, hibernation, snapshot, rollback.