.BR \-a , " \-\-all"
All of the filesystems described in
.I /proc/self/mountinfo
-(or in deprecated /etc/mtab)
+(or in deprecated
+.IR /etc/mtab )
are unmounted, except the proc, devfs, devpts, sysfs, rpc_pipefs and nfsd
filesystems. This list of the filesystems may be replaced by \fB\-\-types\fR
umount option.
The filesystem can be specified by one of the mountpoints or the device name (or
UUID, etc.). When this option is used together with \fB\-\-recursive\fR, then
all nested mounts within the filesystem are recursively unmounted.
-This option is only supported on systems where /etc/mtab is a symlink
-to /proc/mounts.
+This option is only supported on systems where
+.I /etc/mtab
+is a symlink
+to
+.IR /proc/mounts .
.TP
.BR \-c , " \-\-no\-canonicalize"
Do not canonicalize paths. The paths canonicalization is based on
or special file representing that namespace.
.sp
.BR umount (8)
-switches to the namespace when it reads /etc/fstab, writes /etc/mtab (or writes to /run/mount) and calls
+switches to the namespace when it reads
+.IR /etc/fstab ,
+writes
+.IR /etc/mtab
+(or writes to
+.IR /run/mount )
+and calls
.BR umount (2)
system call, otherwise it runs in the original namespace.
It means that the target mount namespace does not have
.BR \-R , " \-\-recursive"
Recursively unmount each specified directory. Recursion for each directory will
stop if any unmount operation in the chain fails for any reason. The relationship
-between mountpoints is determined by /proc/self/mountinfo entries. The filesystem
+between mountpoints is determined by
+.I /proc/self/mountinfo
+entries. The filesystem
must be specified by mountpoint path; a recursive unmount by device name (or UUID)
is unsupported.
.TP
Note that
.B umount
reads information about mounted filesystems from kernel (/proc/mounts) and
-filesystem names may be different than filesystem names used in the /etc/fstab
+filesystem names may be different than filesystem names used in the
+.I /etc/fstab
(e.g., "nfs4" vs. "nfs").
.TP
.BR \-v , " \-\-verbose"
.B umount
command will automatically detach loop device previously initialized by
.BR mount (8)
-command independently of /etc/mtab.
+command independently of
+.IR /etc/mtab .
In this case the device is initialized with "autoclear" flag (see
.BR losetup (8)
.TP
.I /etc/mtab
table of mounted filesystems (deprecated and usually replaced by
-symlink to /proc/mounts)
+symlink to
+.IR /proc/mounts )
.TP
.I /etc/fstab
table of known filesystems