HP-UX Reference (11i v2 07/12) - 1M System Administration Commands A-M (vol 3)

m
mount_memfs(1M) mount_memfs(1M)
NAME
mount_memfs: mount, umount - mount and unmount MemFS file systems
SYNOPSIS
/usr/sbin/mount
[-l][-p|-v
]
/usr/sbin/mount -a
[-F memfs][-eQ
]
/usr/sbin/mount
[-F memfs][-eQV][
-o specific_options] directory
/usr/sbin/umount -a
[-F memfs][
-v]
/usr/sbin/umount
[-v][-V] directory
DESCRIPTION
The
mount command mounts file systems. Only a superuser can mount file systems. Other users can use
mount to list mounted file systems.
The mount command attaches a removable file system, to directory, a directory on the file tree. directory,
which must already exist, will become the name of the root of the newly mounted file system. directory
must be given as an absolute path name.
mount can be invoked on any removable file system, except the / directory.
It is important to note that
mount_memfs does an internal mkfs and hence a separate mkfs is not
needed for MemFS filesystems. It constructs the MemFS filesystem in the buffer cache. The MemFS
blocks will be swapped out of buffer cache when there is buffer cache or system memory pressure. MemFS
blocks that are swapped out of the buffer cache are stored in memory allocated to a user process associated
with every MemFS mount instance. The user process is created during a
mount and destroyed with a
corresponding umount.
The tunable
memfs_bufcache_swappct
can be used to mark the threshold for swapping out MemFS
blocks from the buffer cache to the user process (see memfs_bufcache_swappct(5)).
If
mount is invoked without any arguments, it lists all of the mounted file systems from the file system
mount table, /etc/mnttab .
The umount command unmounts mounted file systems. Only a superuser can unmount file systems.
Options (mount)
mount recognizes the following options:
-a Attempt to mount all file systems described in /etc/fstab . All optional fields in
/etc/fstab must be included and supported. If -F memfs is specified, all MemFS
file systems in /etc/fstab are mounted. If noauto is specified in an entry’s option
list, this entry is skipped. File systems are not necessarily mounted in the order listed in
/etc/fstab .
-e Verbose mode. Write a message to standard output indicating which file system is being
mounted.
-F memfs Specify the MemFS file system type (see fstyp(1M)).
-l Limit actions to local file systems only.
-o specific_options
Specify options specific to the MemFS file system type. specific_options is a list of comma
separated suboptions and/or keyword/attribute pairs intended for the MemFS specific
module of the command.
The following specific_options are valid on MemFS file systems.
defaults Use all default options.
size The size for the MemFS filesystem. Append to size, kb or KB to indicate the
value is in kilobytes, mb or MB to indicate megabytes, or gb or GB to indi-
cate gigabytes.
The default value is the percentage of maximum buffer cache size that can
be occupied by MemFS, as specified by the memfs_bufcache_swappct
tunable. The size of MemFS file systems is limited by UFS_MAXDEVBLK,
defined in <sys/fs.h> , which is 256 GB - 1, or 268,435,455 blocks.
598 Hewlett-Packard Company − 1 − HP-UX 11i Version 2: December 2007 Update