Unmounting a File System
Unmounting a file system removes it from the file system mount point. Some file system administration tasks cannot be performed on mounted file systems. You should unmount a file system under these circumstances:
When it is no longer needed
When you check and repair it by using the fsck command
When you are about to do a complete backup of it
To unmount a file system, use the umount command:
<mount-point> is the name of the file system you want to unmount. This can be either the directory name in which the file system is mounted or the device name path of the file system. For example, to unmount the /home2 file system, type the following:
Alternatively, you can specify the device ...