Lazy commit is an important feature of NTFS. It allows NTFS to minimize the cost of logging to maintain high performance.
Lazy commit is similar to lazy write. Instead of using system resources to mark a transaction as successfully completed as soon as it is performed, the commitment information is cached and written to the log as a background process. If the power source or computer system should fail before the commit is logged, NTFS rechecks the transaction to see whether it was successfully completed. If NTFS cannot guarantee that the transaction was completed successfully, it backs out the transaction. No incomplete modifications to the volume are allowed.
Every few seconds, NTFS checks the cache to determine the status of the lazy writer and marks the status as a checkpoint in the log. If the system crashes subsequent to that checkpoint, the system backs up to that checkpoint for recovery. This method makes recovery faster by minimizing the number of queries that are required during recovery.