An overlay optimizer can be configured to accelerate the moving of files from an overlay and to atomically move files from the overlay. To accelerate the moving of files from the overlay, the overlay optimizer can continuously monitor the consumption of the overlay. If the consumption exceeds an optimized threshold, the overlay optimizer can cause the file system cache to be invalidated to thereby release handles to any closed files that are still cached. To move files atomically from the overlay, the overlay optimizer can be configured to handle attempts to open a file by determining whether the file is in the process of being moved from the overlay. If so, the overlay optimizer can detect which stage the move process has reached and can dynamically adapt the move process to enable the attempt to open the file to be completed successfully and in a consistent manner.