In the command 'mount -o remount,nosuid /tmp', what does 'remount' signify?

The term 'remount' in the command 'mount -o remount,nosuid /tmp' specifically refers to the action of attempting to remount an already mounted filesystem with new options. When you use 'remount', the operating system will not unmount the existing filesystem but instead will modify its mount options without needing to first unmount it. This is particularly useful for applying changes to the mount settings, such as altering permissions or enforcing security measures, like the 'nosuid' option, which disables the set-user-identifier or set-group-identifier bits.

This feature is essential in system administration for maintaining running systems without interruption, as unmounting can lead to downtime or temporary access issues for users and services that depend on that filesystem. The ability to modify mount options dynamically aids in maintaining optimal system security and functionality.