Most file systems store and maintain three separate time stamps per file. They are
- create time
- last modified time
- last accessed time
The last accessed time stamp may have to be updated quite frequently. For example, listing the directory contents will make all the containing files to get a new last accessed time stamps – this causes additional writes and adding to the file system overhead. The filesystem mount option “noatime” can be used to disable the last accessed time stamp updates to the filesystem, resulting in reduced file system overhead. File systems with lot of small files (like file servers, home areas) will experience noticeable improvement in performance.