Why is it essential to pause IO prior to creating a snapshot?

Pausing I/O operations before creating a snapshot is essential to ensure data consistency. When a snapshot is taken, it captures the current state of the data at a specific point in time. If I/O operations are occurring simultaneously—such as writes, reads, or updates—there's a risk that the snapshot could capture a state where the data is partially written, potentially leading to inconsistencies or corrupted data states. This is particularly important for applications that involve transactions or require precise data integrity, such as databases.

By pausing I/O, you create a stable image of the data, ensuring that all writes are completed and no changes are in progress. This capability helps maintain the reliability of the data when the snapshot is restored or accessed later, thus safeguarding against potential issues that could arise from any ongoing operations.

While improving performance, reducing storage costs, or speeding up the snapshot process are valid considerations in storage management, they do not directly address the critical requirement of capturing a reliable and consistent state of the data during the snapshot process.