mount(1m) DG/UX 4.30 mount(1m)
NAME
mount, umount - mount and dismount filesystems
SYNOPSIS
mount [ -p ]
mount -a[fnv] [ -t type ]
mount [ -fnrv ] [ -t type ] [ -o options ] filesystem
directory
mount [ -vfn ] [ -o options ] filesystem | directory
umount [ -t type ] [ -h host ]
umount -a[v]
umount [ -v ] filesystem | directory ...
DESCRIPTION
The /etc/mount program attaches a named filesystem to the
filesystem hierarchy at the pathname location directory,
which must already exist. If directory has any contents
prior to the mount operation, these remain hidden until the
filesystem is once again unmounted. If filesystem is of the
form host:pathname, it is assumed to be an NFS filesystem
(type nfs).
The /etc/umount program detaches or "unmounts" a currently
mounted filesystem, which can be specified either as a
directory or as a filesystem.
mount and umount maintain a table of mounted filesystems in
/etc/mnttab, described in fstab(4). If invoked without an
argument, mount displays the contents of this table. If
invoked with either a filesystem or directory only, mount
searches the file /etc/fstab for a matching entry, and
mounts the filesystem indicated in that entry on the
indicated directory.
MOUNT OPTIONS
-p Print the list of mounted filesystems in a format
suitable for use in /etc/fstab.
-a All. Attempt to mount all the filesystems described in
/etc/fstab. If a type argument is specified with -t,
mount all filesystems of that type. Filesystems are
not necessarily mounted in the order shown in
/etc/fstab.
-f Fake an /etc/mnttab entry, but do not actually mount
any filesystems.
-n Mount the filesystem without making an entry in
/etc/mnttab.
-v Verbose. Display a message indicating each filesystem
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being mounted.
-t type
Specify a filesystem type. The accepted types are
dg/ux, cdrom, swap, and nfs; see fstab(4) for a
description of these types.
-r Mount the specified filesystem read-only, even if the
entry in /etc/fstab specifies that it is to be mounted
read-write.
Physically write-protected and magnetic-tape
filesystems must be mounted read-only. Otherwise errors
occur when the system attempts to update access times,
even if no write operation is attempted.
-o options
Specify filesystem options -list of comma-separated
words from the list below. Some options are valid for
all filesystem types, while others apply to a specific
type only.
options valid on all filesystems:
rw|ro Read/write or read-only.
nosuid Setuid execution disallowed.
noauto Do not mount this filesystem that is
currently mounted read-only. If the
filesystem is not currently mounted, an
error results.
The default is `rw,suid'.
Options specific to memory (MFS) filesystems (see
mfs(4)):
ramdisk This is how you specify the mount of a
memory file system.
usewiredmemory
This specifies that you want wired memory
instead of unwired memory (the default)
for the memory file system. Using wired
memory insures that data in the memory
file system does not move to the swap
area, insuring quick access to the data
in the file system.
maxfilespace=n
The default number of blocks in a memory
file system is 1024. This option allows
that maximum to be increased or decreased
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to the value n blocks. No memory is
allocated until it is actually used to
store data in a memory file system;
therefore, there is no assurance that the
maximum will ever be reached. For
example, if you set the number of blocks
to be greater than the number in the
system and set the usewiredmemory flag,
there is no way to allocate the maximum
because there is not that much wired
memory in the system. Attempts to
allocate more than is available will
result in a simple failure to allocate
more space in the file system.
maxfilecount=n
The default number of file nodes that can
be allocated in a memory file system is
16384. Using this option allows you to
increase or decrease this maximum. As in
the option maxfilespace, there is no
assurance that you will be able to obtain
the maximum number of nodes that you set
via this option.
Options specific to nfs (NFS) filesystems:
bg|fg If the first attempt fails, retry in the
background, or, in the foreground.
secure Requires clients to use a more secure
protocol when accessing the directory.
Secure RPC using DES Authentication is an
additional feature that must be purchased
separately from the DG/UXTM ONCTM/NFS
product. You must have this feature to
use the secure option.
retry=n The number of times to retry the mount
operation.
rsize=n Set the read buffer size to n bytes.
wsize=n Set the write buffer size to n bytes.
timeo=n Set the NFS timeout to n tenths of a
second.
retrans=n The number of NFS retransmissions.
port=n The server IP port number.
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soft|hard Return an error if the server does not
respond, or continue the retry request
until the server responds.
acregmin=n Hold cached attributes for at least n
seconds after file modification.
acregmax=n Hold cached attributes for no more than n
seconds after file modification.
acdirmin=n Hold cached attributes for at least n
seconds after directory update.
acdirmax=n Hold cached attributes for no more than n
seconds after directory update.
actimeo=n Set min and max times for regular files
and directories to n seconds.
Regular defaults are:
fg,retry=10000,timeo=7,retrans=3,port=NFSPORT,hard,\
acregmin=3,acregmax=60,acdirmin=30,acdirmax=60
Defaults for rsize and wsize are set internally by
the system kernel.
UMOUNT OPTIONS
-h host Unmount all filesystems listed in /etc/mnttab that
are remote-mounted from host.
-t type Unmount all filesystems listed in /etc/mnttab that
are of a given type.
-a Unmount all filesystems currently mounted (as
listed in /etc/mnttab).
-v Verbose. Display a message indicating each
filesystem being unmounted.
NFS FILESYSTEMS
Background vs. Foreground
Filesystems mounted with the bg option indicate that mount
is to retry in the background if the server's mount daemon
(mountd(8c)) does not respond. mount retries the request up
to the count specified in the retry=n option. Once the
filesystem is mounted, each NFS request made in the kernel
waits timeo=n tenths of a second for a response. If no
response arrives, the time-out is multiplied by 2 and the
request is retransmitted. When the number of
retransmissions has reached the number specified in the
retrans=n option, a filesystem mounted with the soft option
returns an error on the request; one mounted with the hard
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option prints a warning message and continues to retry the
request.
Read-Write vs. Read-Only
Filesystems that are mounted rw (read-write) should use the
hard option.
File Attributes
The attribute cache retains file attributes on the client.
Attributes for a file are assigned a time to be flushed. If
the file is modified before the flush time, then the flush
time is extended by the time since the last modification
(under the assumption that files that changed recently are
likely to change soon). There is a minimum and maximum
flush time extension for regular files and for directories.
Setting actimeo=n extends flush time by n seconds for both
regular files and directories.
EXAMPLES
To mount a local disk:
mount /dev/dsk/usr /usr
To mount all DG/UX filesystems:
mount -at dg/ux
To mount a remote filesystem:
mount -t nfs serv:/usr/src /usr/src
To mount a remote filesystem:
mount serv:/usr/src /usr/src
To hard mount a remote filesystem:
mount -o hard serv:/usr/src /usr/src
To save current mount state:
mount -p > /etc/fstab
To mount a memory file system (the name /dev/memtmp is
arbitrary and will be created by the mount command):
mount -o ramdisk /dev/memtmp /mnt
To mount a memory file system using wired memory:
mount -o ramdisk,usewiredmemory /dev/memtmp2 /memory1
FILES
/etc/mnttab table of mounted filesystems
/etc/fstab table of filesystems mounted at boot
SEE ALSO
mkdir(2), dg_mount(2), umount(2), open(2), fstab(4),
mnttab(4), mountd(8C), nfsd(8) mfs(4) fs(4)
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/usr/include/sys/dg_mount.h /usr/include/sys/nfs.h
BUGS
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 points, rather than being mounted on
top of the symbolic link itself.
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