mount_kernfs(8) [netbsd man page]

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

NAME

     mount_kernfs -- mount the /kern file system

SYNOPSIS

     mount_kernfs [-o options] /kern mount_point

DESCRIPTION

     The mount_kernfs command attaches an instance of the kernel parameter namespace to the global filesystem namespace.  The conventional mount
     point is /kern.  The directory specified by mount_point is converted to an absolute path before use.  This command is normally executed by
     mount(8) at boot time.

     The filesystem includes several regular files which can be read, some of which can also be written.  The contents of the files is in a
     machine-independent format, either a string, or an integer in decimal ASCII.  Where numbers are returned, a trailing newline character is
     also added.

     The options are as follows:

     -o      Options are specified with a -o flag followed by a comma separated string of options.  See the mount(8) man page for possible options
	     and their meanings.

FILES

     boottime	the time at which the system was last booted (decimal ASCII).
     copyright	kernel copyright message.
     hostname	the hostname, with a trailing newline.	The hostname can be changed by writing to this file.  A trailing newline will be stripped
		from the hostname being written.
     hz 	the frequency of the system clock (decimal ASCII).
     ipsecsa	the directory that contains IPsec security associations (SA) in PF_KEY format.	Filenames are SPI in decimal number.  The content
		of files can be inspected by using setkey(8).
     ipsecsp	the directory that contains IPsec security policies in PF_KEY format.  Filenames are security policy ID in decimal number.  The
		content of files can be inspected by using setkey(8).
     loadavg	the 1, 5 and 15 minute load average in kernel fixed-point format.  The final integer is the fix-point scaling factor.  All numbers
		are in decimal ASCII.
     msgbuf	the kernel message buffer, also read by syslogd(8), through the log device, and by dmesg(8).
     pagesize	the machine pagesize (decimal ASCII).
     physmem	the number of pages of physical memory in the machine (decimal ASCII).
     rootdev	the root device.
     rrootdev	the raw root device.
     time	the second and microsecond value of the system clock.  Both numbers are in decimal ASCII.
     version	the kernel version string.  The head line for /etc/motd can be generated by running: ``sed 1q /kern/version''

SEE ALSO

     mount(2), unmount(2), ipsec(4), fstab(5), dmesg(8), mount(8), setkey(8), syslogd(8)

HISTORY

     The mount_kernfs utility first appeared in 4.4BSD.

BUGS

     This filesystem may not be NFS-exported.

     lkm(4) version does not support IPsec-related files/directories.

BSD
								 September 8, 2003							       BSD

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

NAME

     mount_tmpfs -- mount an efficient memory file system

SYNOPSIS

     mount_tmpfs [-g group] [-m mode] [-n nodes] [-o options] [-s size] [-u user] tmpfs mount_point

DESCRIPTION

     The mount_tmpfs command attaches an instance of the efficient memory file system to the global file system namespace.  The tmpfs parameter
     only exists for compatibility with the other mount commands and is ignored.  The directory specified by mount_point is converted to an abso-
     lute path before use and its attributes (owner, group and mode) are inherited unless explicitly overriden by the options described below.

     The following options are supported:

     -g group	 Specifies the group name or GID of the root inode of the file system.	Defaults to the mount point's GID.

     -m mode	 Specifies the mode (in octal notation) of the root inode of the file system.  Defaults to the mount point's mode.

     -n nodes	 Specifies the maximum number of nodes available to the file system.  If not specified, the file system chooses a reasonable maxi-
		 mum given its size at mount time, which can be limited with -s.

     -o options  Options are specified with a -o flag followed by a comma-separated string of options.	See the mount(8) man page for possible
		 options and their meanings.

     -s size	 Specifies the total file system size in bytes.  If zero is given (the default), the available amount of memory (including main
		 memory and swap space) will be used.  Note that four megabytes are always reserved for the system and cannot be assigned to the
		 file system.

     -u user	 Specifies the user name or UID of the root inode of the file system.  Defaults to the mount point's UID.

     Every option that accepts a numerical value as its argument can take a trailing 'b' to indicate bytes (the default), a trailing 'k' to indi-
     cate kilobytes, a trailing 'M' to indicate megabytes or a trailing 'G' to indicate gigabytes.  Note that both lowercase and uppercase forms
     of these letters are allowed.

EXAMPLES

     The following command mounts a tmpfs instance over the /tmp directory, inheriting its owner, group and mode settings:

     mount -t tmpfs tmpfs /tmp

     The following command mounts a tmpfs instance over the /mnt directory, setting a 20 megabytes limit in space, owned by the 'joe' user and
     belonging to the 'users' group, with a restricted 0700 mode:

     mount -t tmpfs -o -s20M -o -ujoe -o -gusers -o -m0700 tmpfs /mnt

     See /usr/share/examples/fstab/fstab.ramdisk for some examples on how to add tmpfs entries to /etc/fstab.

SEE ALSO

     fstab(5), mount(8)

HISTORY

     The mount_tmpfs utility first appeared in NetBSD 4.0.

BUGS

     File system meta-data is not pageable.  If there is not enough main memory to hold this information, the system may become unstable or very
     unresponsive because it will not be able to allocate required memory.  A malicious user could trigger this condition if he could create lots
     of files inside a size-unbounded tmpfs file system.  Limiting the number of nodes per file system (-n) will prevent this; the default value
     for this setting is also often adjusted to an adequate value to resolve this.

BSD
								 February 13, 2008							       BSD