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umount ? unmount file systems |
umount [?hV] umount -a [?nrv] [?t
vfstype] |
The umount command detaches the file system(s) mentioned from the file hierarchy. A file system is specified either by giving the directory where it has been mounted, or by giving the special device on which it lives. 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. Options for the umount command: |
?V |
Print version and exit. |
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?h |
Print help message and exit. |
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?v |
Verbose mode. |
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?n |
Unmount without writing in /etc/mtab. |
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?r |
In case unmounting fails, try to remount read-only. |
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?a |
All of the file systems described in /etc/mtab are unmounted. (With umount version 2.7 and later: the proc filesystem is not unmounted.) |
?t vfstype |
Indicate that the actions should only be taken on file systems of the specified type. More than one type may be specified in a comma separated list. The list of file system types can be prefixed with no to specify the file system types on which no action should be taken. |
?f |
Force unmount (in case of an unreachable NFS system). (Requires kernel 2.1.116 or later.) |
The umount command will free the loop device (if any) associated with the mount, in case it finds the option ‘loop=...’ in /etc/mtab. Any pending loop devices can be freed using ‘losetup -d’, see losetup(8). |
/etc/mtab table of mounted file systems |
umount(2), mount(8), losetup(8). |
A umount command appeared in Version 6 AT&T UNIX. |