'\"macro stdmacro
.if n .pH g1a.mount_nfs @(#)mount_nfs	40.10 of 1/17/90
.\" Copyright 1989 AT&T
.nr X
.if \nX=0 .ds x} mount 1M "NFS" "\&"
.if \nX=1 .ds x} mount 1M "NFS"
.if \nX=2 .ds x} mount 1M "" "\&"
.if \nX=3 .ds x} mount "" "" "\&"
.TH \*(x}
.SH NAME
\f4mount\f1 \- mount remote NFS resources
.SH SYNOPSIS
\f4mount\f1
[
\f4\-F nfs\f1
]
[
\f4\-r\f1
]
[
\f4\-o\f2 specific_options\f1
]
[
\f2resource mountpoint\f1 
]
.SH DESCRIPTION
The
\f4mount\f1
command 
attaches a named
\f2resource\f1
to the file system hierarchy at the pathname location
.IR mountpoint ,
which must already exist.
If
\f2mountpoint\f1
has any contents prior to the
\f4mount\f1
operation, the contents remain hidden until the
\f2resource\f1
is once again unmounted.
.\"If
.\".I resource
.\"is of the form
.\".IB host : pathname,
.\"it is assumed to be an
.\".SM NFS
.\"file system (type
.\".BR nfs ).
.LP
If the resource is listed in the \f4vfstab\f1 file, the command line
can specify either \f2resource\f1 or \f2mountpoint\f1, and \f4mount\f1
will consult \f4vfstab\f1 for more information.  If
the \f4\-F\f1 option is omitted, \f4mount\f1 will take the
file system type from \f4vfstab\f1. 
.LP
\f4mount\f1
maintains a table of mounted file systems in
\f4/etc/mnttab\f1,
described in
\f4mnttab\f1(4).
.LP
The following options are available to the
\f4mount\f1
command:
.TP
\f4\-r\f1
Mount the specified file system read-only.
.TP
\f4\-o\f2 specific_options\f1
Specify file system specific options in a
comma-separated list of words from the list below.
.RS
.TP 14
\f4rw\f1\||\|\f4ro\f1
\f2resource\f1
is mounted read-write or read-only.
The default is
\f4rw\f1.
.PD 0
.TP
\f4suid\f1\||\|\f4nosuid\f1
Setuid execution allowed or disallowed.
The default is
\f4suid\f1.
.TP
\f4remount\f1
If a file system is mounted read-only,
remounts the file system read-write.
.TP
\f4bg\f1\||\|\f4fg\f1
If the first attempt fails, retry in the background, or,
in the foreground.
The default is
\f4fg\f1.
.TP
\f4retry=\f2n\f1
The number of times to retry the mount operation.
The default is 10000.
.TP
\f4port=\f2n\f1
The server
.SM IP
port number.
The default is
\f4NFS_PORT\f1.
.TP
\f4grpid\f1
Create a file with its
.SM GID 
set to the effective 
.SM GID
of the calling process.
This behavior may be overridden on a per-directory basis
by setting the set-\s-1GID\s0 bit of the parent directory;
in this case, the 
.SM GID
is set to the 
.SM GID
of the parent directory [see
\f4open\f1(2)
and
\f4mkdir\f1(2)].
Files created on file systems that are 
\f2not\f1
mounted with the
\f4grpid\f1
option will obey 
.SM BSD 
semantics;
that is, the 
.SM GID
is unconditionally inherited from that of
the parent directory.
.TP
\f4rsize=\f2n\f1
Set the read buffer size to
.I n
bytes.
.TP
\f4wsize=\f2n\f1
Set the write buffer size to
\f2n\f1
bytes.
.TP
\f4timeo=\f2n\f1
Set the
.SM NFS
timeout to
\f2n\f1
tenths of a second.
.TP
\f4retrans=\f2n\f1
Set the number of
.SM NFS
retransmissions to
\f2n\f1.
.TP
\f4soft\f1\||\|\f4hard\f1
Return an error if the server does not respond,
or continue the retry request until the server responds.
.TP
\f4intr\f1
Allow keyboard interrupts to kill a process that is hung
while waiting for a response on a hard-mounted file
system.
.TP
\f4secure\f1
Use a more secure protocol for
.SM NFS
transactions.
.TP
\f4noac\f1
Suppress attribute caching.
.TP
\f4acregmin=\f2n\f1
Hold cached attributes for at least
\f2n\f1
seconds after file modification.
.TP
\f4acregmax=\f2n\f1
Hold cached attributes for no more than
\f2n\f1
seconds after file modification.
.TP
\f4acdirmin=\f2n\f1
Hold cached attributes for at least
\f2n\f1
seconds after directory update.
.TP
\f4acdirmax=\f2n\f1
Hold cached attributes for no more than
\f2n\f1
seconds after directory update.
.TP
\f4actimeo=\f2n\f1
Set
\f2min\f1
and
\f2max\f1
times for regular files and directories to
\f2n\f1
seconds.
.PD
.RE
.SH NFS FILE SYSTEMS
.SS Background vs. Foreground
File systems mounted with the
\f4bg\f1
option indicate that
\f4mount\f1
is to retry in the background if the server's mount daemon
[\f4mountd\f1(1M)]
does not respond.
\f4mount\f1
retries the request up to the count specified in the
\f4retry=\f2n\f1
option.
Once the file system is mounted, each
.SM NFS
request made in the kernel waits
\f4timeo=\f2n\f1
tenths of a second for a response.
If no response arrives, the
time-out is multiplied by
\f42\f1
and the request is retransmitted.
When the number of
retransmissions has reached the number specified in the
\f4retrans=\f2n\f1
option, a file system mounted with the
\f4soft\f1
option returns an error on the request; one mounted with the
\f4hard\f1
option prints a warning message and continues to retry the request.
.SS Read-Write vs. Read-Only
.LP
File systems that are mounted
\f4rw\f1
(read-write) should use the
\f4hard\f1
option.
.SS Secure File Systems
The
\f4secure\f1
option must be given if the server requires secure
mounting for the file system.
.SS "File Attributes"
.LP
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
\f4actimeo=\f2n\f1
extends flush time by
\f2n\f1
seconds for both regular files and directories.
.SH EXAMPLES
To mount a remote file system: \f4mount \-F nfs serv:/usr/src /usr/src\f1
.br
To hard mount a remote file system: \f4mount \-o hard serv:/usr/src /usr/src\f1
.br
.ne 1i
.PD
.SH FILES
.PD 0
.TP 20
\f4/etc/mnttab\f1
table of mounted file systems
.TP
\f4/etc/dfs/fstypes\f1
default distributed file system type
.TP
\f4/etc/vfstab\f1
table of automatically mounted resources
.PD
.SH "SEE ALSO"
\f4mountall\f1(1M),
\f4mount\f1(2),
\f4umount\f1(2),
\f4mnttab\f1(4).
.SH NOTES
.LP
If the directory on which a file system is to be mounted is a
symbolic link, the file system is mounted on
.I "the directory to which the symbolic link refers,"
rather than being mounted on top of the symbolic link itself.
