Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

umount(8) [netbsd man page]

UMOUNT(8)						    BSD System Manager's Manual 						 UMOUNT(8)

NAME
umount -- unmount filesystems SYNOPSIS
umount [-fvFR] [-t fstypelist] special | node umount -a [-fvF] [-h host] [-t fstypelist] DESCRIPTION
The umount command calls the unmount(2) system call to remove a special device or the remote node (rhost:path) from the filesystem tree at the point node. If either special or node are not provided, the appropriate information is taken from the fstab(5) file. The options are as follows: -a All the currently mounted filesystems except the root are unmounted. -f The filesystem is forcibly unmounted. Active special devices continue to work, but all other files return errors if further accesses are attempted. The root filesystem cannot be forcibly unmounted. -F Fake the unmount; perform all other processing but do not actually attempt the unmount. (This is most useful in conjunction with -v, to see what umount would attempt to do). -R Take the special | node argument as a path to be passed directly to unmount(2), bypassing all attempts to be smart about mechanically determining the correct path from the argument. This option is incompatible with any option that potentially unmounts more than one filesystem, such as -a, but it can be used with -f and/or -v. This is the only way to unmount something that does not appear as a directory (such as a nullfs mount of a plain file); there are probably other cases where it is necessary. -h host Only filesystems mounted from the specified host will be unmounted. This option is implies the -a option and, unless otherwise spec- ified with the -t option, will only unmount NFS filesystems. -t fstypelist Is used to indicate the actions should only be taken on filesystems of the specified type. More than one type may be specified in a comma separated list. The list of filesystem types can be prefixed with ``no'' to specify the filesystem types for which action should not be taken. For example, the umount command: umount -a -t nfs,mfs unmounts all filesystems of the type NFS and MFS, whereas the umount command: umount -a -t nonfs,mfs unmounts all file systems except those of type NFS and MFS. -v Verbose, additional information is printed out as each filesystem is unmounted. FILES
/etc/fstab filesystem table SEE ALSO
unmount(2), fstab(5), mount(8) HISTORY
A umount command appeared in Version 6 AT&T UNIX. BSD
May 17, 2009 BSD

Check Out this Related Man Page

UMOUNT(8)						     Linux Programmer's Manual							 UMOUNT(8)

NAME
umount - unmount file systems SYNOPSIS
umount [-hV] umount -a [-dflnrv] [-t vfstype] [-O options] umount [-dflnrv] {dir|device}... DESCRIPTION
The umount command detaches the file system(s) mentioned from the file hierarchy. A file system is specified by giving the directory where it has been mounted. Giving the special device on which the file system lives may also work, but is obsolete, mainly because it will fail in case this device was mounted on more than one directory. 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. Options for the umount command: -V Print version and exit. -h Print help message and exit. -v Verbose mode. -n Unmount without writing in /etc/mtab. -r In case unmounting fails, try to remount read-only. -d In case the unmounted device was a loop device, also free this loop device. -i Don't call the /sbin/umount.<filesystem> helper even if it exists. By default /sbin/umount.<filesystem> helper is called if one exists. -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. -O options Indicate that the actions should only be taken on file systems with the specified options in /etc/fstab. More than one option type may be specified in a comma separated list. Each option can be prefixed with no to specify options for which no action should be taken. -f Force unmount (in case of an unreachable NFS system). (Requires kernel 2.1.116 or later.) -l Lazy unmount. Detach the filesystem from the filesystem hierarchy now, and cleanup all references to the filesystem as soon as it is not busy anymore. (Requires kernel 2.4.11 or later.) --no-canonicalize Don't canonicalize paths. For more details about this option see the mount(8) man page. THE LOOP DEVICE
The umount command will free the loop device (if any) associated with the mount, in case it finds the option `loop=...' in /etc/mtab, or when the -d option was given. Any pending loop devices can be freed using `losetup -d', see losetup(8). NOTES
The syntax of external umount helpers is: /sbin/umount.<suffix> {dir|device} [-nlfvr] where the <suffix> is filesystem type or a value from "uhelper=" mtab option. The uhelper (unprivileged umount helper) is possible to used when non-root user wants to umount a mountpoint which is not defined in the /etc/fstab file (e.g devices mounted by HAL). FILES
/etc/mtab table of mounted file systems SEE ALSO
umount(2), mount(8), losetup(8). HISTORY
A umount command appeared in Version 6 AT&T UNIX. AVAILABILITY
The umount command is part of the util-linux-ng package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux-ng/. Linux 2.0 26 July 1997 UMOUNT(8)
Man Page