umount -fl用法

umount, 老是提示：device is busy， 服务又不能停止的。可以用"umount -fl"解决!

挂载：

mount - mount a filesystem

mount [options] device dir

如：mount --bind /dev  /home/tmp/dev

解挂载：

umount - unmount a filesystem

umount [options] dir

如：umount  /home/tmp/dev

Note that a file system cannot be unmounted when it is 'busy' - for example, when there are open files on it, or when some process has its working directory there, or when a swap file on it is in use. The offending process could even be umount itself - it opens libc, and libc in its turn may open for example locale files. A lazy unmount avoids this problem。

       -f, --force
              Force an unmount (in case of an unreachable NFS system).

              Note that this option does not guarantee that umount command
              does not hang.  It's strongly recommended to use absolute
              paths without symlinks to avoid unwanted readlink and stat
              system calls on unreachable NFS in umount.

       -l, --lazy
              Lazy unmount.  Detach the filesystem from the file hierarchy
              now, and clean up all references to this filesystem as soon as
              it is not busy anymore.