read write or read only mode. Explicitly defining a file system as rw can alleviate some problems in file systems that default to read only, as can be the case with floppies or NTFS partitions. sync / async How the input and output to the filesystem should be done. sync means it is done synchronously. Looking at the example fstab, this is the option used with the floppy. This means that when, for example, a file is copied to the floppy, the changes are physically written to the floppy at the same time copy command is issued. suid / nosuid Controls the behavior of the operation of suid, and sgid bits. user / users / nouser user permits any user to mount the filesystem. This automatically implies noexec, nosuid, nodev unless explicitly overridden. If nouser is specified, only root can mount the filesystem. If users is specified, every user in group users will be able to unmount the volume. defaults Use default settings. Default settings are defined per file system at the file system level. For ext3 file systems these can be set with the tune2fs command. The normal default for ext3 file systems is equivalent to rw,suid,dev,exec,auto,nouser,async. Modern Red Hat based systems set ACL support as default on the root file system but not on user-created ext3 filesystems. Some file systems such as XFS enable ACLs by default. Default file system mount attributes can be overridden in /etc/fstab. owner (Linux-specific) Permit the owner of device to mount. atime / noatime / relatime / strictatime (Linux-specific) The Unix stat structure records when files are last accessed (atime), modified (mtime), and changed (ctime). One result is that atime is written every time a file is read, which has been heavily criticized for causing performance degradation and increased wear. However, atime is used by some applications and desired by some users, and thus is configurable as atime (update on access), noatime (do not update), or (in Linux) relatime (update atime if older than mtime). Through Linux 2.6.29, atime was the default; as of 2.6.30, relatime is the default. Filesystem-specific options There are many options for the specific filesystems supported by mount. Listed below are some of the more commonly used. The full list may be found in the documentation for mount. Note that these are for Linux; traditional Unix-like systems have generally provided similar functionality but with slightly different syntax or forms.