mount_memfs(1M)
mount_memfs --
mount memfs filesystems
Synopsis
mount [-F memfs] [generic_options] [-r] [-o specific_options]
[special|mount_point]
mount [-F memfs] [generic_options] [-r] [-o specific_options]
special mount_point
mount-
mount memfs filesystems
Description
generic_options are options supported by the generic mount command.
mount
attaches a
memfs
filesystem to the filesystem 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
filesystem is once again unmounted.
The options are:
-F memfs-
Specifies the memfs file system type
-o-
Specifies memfs filesystem specific options in a comma-separated list.
If invalid options are specified, a warning message
is printed and the invalid options are ignored.
Multiple filesystem-specific options may be listed in any order, but
must be separated by commas.
The following options are available:
swapmax-
Maximum amount of memory, in bytes, this mounted filesystem is allowed
to use.
Default is the maximum value of an unsigned integer.
global_swapmax-
Maximum amount of memory, in bytes, all memfs filesystems mounted
without specifying 'swapmax' are allowed to use.
Default is the maximum value of an unsigned integer.
rootmode-
Specifies the mode of the root directory of the mounted file
system. Default is 0775.
-r-
Mount the filesystem read only.
Usage
The swapmax and global_swapmax options are mutually
exclusive and cannot be specified on one command line (if they are,
the command fails with EINVAL):
-
The swapmax option specifies memory to be used exclusively for the
file system being mounted.
-
A file system mounted with swapmax ignores any
global_swapmax established on previous mounts (for compatibility).
-
The global_swapmax option specifies memory to be used as a pool
by all memfs file systems mounted without the swapmax
option.
-
A file system mounted without swapmax, or without either option,
shares the currently defined global_swapmax memory pool.
-
The initial value of global_swapmax on initial system installation
is infinity (in order to be compatible with currently installed systems).
-
When a memfs mount is initiated
specifying a new global_swapmax, then either:
-
the mount will fail (returning EBUSY) if the new value of
global_swapmax is less than the total space occupied by
all currently mounted memfs file systems, or
-
the mount will succeed and replace the current value
of global_swapmax with the new value.
The global_swapmax option allows memfs file systems
(like /var/tmp and /tmp) to share the same memory pool,
and both:
-
reduce the overall amount of memory consumed by memfs file systems
-
allow temporary file systems to grow and shrink within a greater amount
of memory than would be available to them individually by using the
swapmax option
Files
/etc/mnttab-
mount table
References
mkdir(2),
mnttab(4),
generic mount(1M),
mount(2),
open(2),
umount(2)
Notices
If the directory on which a filesystem is to be mounted is a
symbolic link, the filesystem is mounted on
the directory to which the symbolic link refers,
rather than on top of the symbolic link itself.
mount_memfs will set the root mode's owner and group information
to bin, effectively doing a chown and chgrp.
Mounting an memfs filesystem creates an instantiation of the
filesystem.
Therefore, there is no corresponding mkfs command required
for the memfs filesystem type.
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 25 April 2004