Abstract: In some embodiments, a file management unit located in the operating system detects a write operation that writes the data blocks within the consistency snapshot (in main memory) to the persistent storage. The file management unit can then determine that all transactions have been completed before the write operation begins. In some instances, the file management unit then attempts to write the data blocks within the consistency snapshot to the persistent storage. The file management unit can then receive a notification that the write operation did not successfully write the data blocks from the consistency snapshot to the persistent storage. In some embodiments, the write operation is not successful because there are fewer free data blocks in the persistent storage than needed for writing the data blocks within the consistency snapshot to persistent storage. The file management can then wait a period of time.