commit

commit

The commit command in Linux forces the system to write all modified data (dirty data) from the buffer cache to disk. This ensures that all pending disk writes are immediately flushed, guaranteeing data integrity in case of a system crash or power outage.

While the operating system automatically performs these writes at regular intervals, commit allows for immediate synchronization. This is useful in situations where critical data must be saved persistently, such as before shutting down after a potentially unstable operation, or to ensure data is safe after certain important procedures.

The command primarily interacts with the sync() system call and is implemented to facilitate the data write to disk. Using commit infrequently improves system performance by allowing the OS to optimize write operations, while its use should be considered in specific data-critical scenarios.

Using commit excessively can degrade system performance as it forces disk writes more frequently than the OS might optimally schedule them.

It's generally not necessary to run commit unless you have specific data integrity concerns.

The most common use case for commit is before a system shutdown or reboot, particularly if the system has been experiencing instability. It can also be valuable in data-intensive applications where ensuring the durability of data is paramount. Be careful, though, to avoid excessive use.

The commit command is a standard part of many Unix-like operating systems, designed to force data to be written from memory to disk immediately. Its primary usage has always been for data integrity and safety, especially in scenarios where data loss is unacceptable. Over the years, the core functionality of the command has remained consistent, serving as a direct trigger for flushing buffers.

sync(1), fsync(2), fdatasync(2)