👉 Copying I/O (CI/O) refers to the process of duplicating data from one storage device or memory location to another, often for the purpose of backup, testing, or performance analysis. In this context, "copied I/O" specifically denotes when the operation involves copying data that has already been read or written to a storage medium, rather than writing new data to it. This can occur in various scenarios, such as when a system is backing up data from a source to a destination, where the copied data is initially read from the source and then written to the copy. Alternatively, it might involve copying data from memory to disk or vice versa, which can be crucial for optimizing performance in high-speed systems or for ensuring data integrity during testing and development. Copying I/O differs from direct I/O (DIO) because it bypasses the original device, potentially reducing latency and improving efficiency.
