Abstract: Methods and systems of a log engine for logging data operation in a file system is disclosed. The log engine includes a user interface module configured to receive a plurality of data operation logs that respectively record a data operation and a sequence ID corresponding to an order of the data operation being performed; and a shared log manager configured to provide an in queue configured to consolidate the plurality of data operation logs, and swap the plurality of data operation logs to an out queue with the plurality of data operation logs being ordered based on the sequence ID and saved in a shared log.