What does crash consistency ensure during unexpected failures?

Crash consistency focuses on ensuring that data remains in a valid state during unexpected failures, such as power outages or sudden system crashes. When a system experiences such interruptions, crash consistency helps to make certain that the data on the storage medium accurately reflects the last completed transactions or operations. This means that any data entries that were not fully processed before the failure will not be mixed with those that were finalized, thus maintaining the integrity of the data throughout the storage system.

Moreover, preserving data integrity is vital for ensuring that applications and services depending on this data can continue functioning correctly after a recovery from the unexpected failure. This way, users can rely on the reliability of the information available to them.

In contrast, while data transmission speed, network connections, and data deletion may relate to other aspects of data management and network resilience, they do not pertain directly to the concept of crash consistency during failures.