MOUNT_TMPFS(8) Maintenance Commands and Procedures MOUNT_TMPFS(8)


mount_tmpfs - mount tmpfs file systems


mount [-F tmpfs] [-o specific_options] [-O] special mount_point


tmpfs is a memory based file system which uses kernel resources relating
to the VM system and page cache as a file system.

mount attaches a tmpfs file system to the file system hierarchy at the
pathname location mount_point, which must already exist. If mount_point
has any contents prior to the mount operation, these remain hidden until
the file system is once again unmounted. The attributes (mode, owner, and
group) of the root of the tmpfs filesystem are inherited from the
underlying mount_point, provided that those attributes are determinable.
If not, the root's attributes are set to their default values. The mode
may also be overridden by the mode mount option, which takes precedence
if set.

The special argument is usually specified as swap but is in fact
disregarded and assumed to be the virtual memory resources within the


-o specific_options
Specify tmpfs file system specific options in a
comma-separated list with no intervening spaces.
If invalid options are specified, a warning
message is printed and the invalid options are
ignored. The following options are available:


Remounts a file system with a
new size. A size not explicitly
set with remount reverts to no

The mode argument controls the
permissions of the tmpfs mount
point. The argument must be an
octal number, of the form
passed to chmod(1). Only the
access mode, setuid, setgid,
and sticky bits (a mask of
07777) may be set. If this
option is not provided then the
default mode behaviour, as
described above, applies.

The sz argument controls the
size of this particular tmpfs
file system. If the argument is
has a `k' suffix, the number
will be interpreted as a number
of kilobytes. An `m' suffix
will be interpreted as a number
of megabytes. A `g' suffix will
be interpreted as a number of
gigabytes. A `%' suffix will be
interpreted as a percentage of
the swap space available to the
zone. No suffix is interpreted
as bytes. In all cases, the
actual size of the file system
is the number of bytes
specified, rounded up to the
physical pagesize of the

xattr | noxattr
Allow or disallow the creation
and manipulation of extended
attributes. The default is
xattr. See fsattr(7) for a
description of extended

Overlay mount. Allow the file system to be
mounted over an existing mount point, making the
underlying file system inaccessible. If a mount is
attempted on a pre-existing mount point without
setting this flag, the mount will fail, producing
the error: device busy.


Table of mounted file systems


mkdir(2), mount(2), open(2), umount(2), tmpfs(4FS), mnttab(5),
attributes(7), fsattr(7), mount(8)


If the directory on which a file system is to be mounted is a symbolic
link, the file system is mounted on the directory to which the symbolic
link refers, rather than on top of the symbolic link itself.

illumos March 18, 2015 MOUNT_TMPFS(8)