.TH EXPORTFS 4
.SH NAME
exportfs, srvfs \- network file server plumbing
.SH SYNOPSIS
.B exportfs
[
.B -asF
] [
.B -r
.I root
]
.PP
.B srvfs
[
.B -p
.I perm
]
.I name
.I dir
.SH DESCRIPTION
.I Exportfs
is a user level file server that allows Plan 9 compute servers, rather
than file servers, to export portions of a name space across networks.
The service is started either by the
.IR cpu (1)
command or by a network listener process.  An initial protocol
establishes a root directory for the exported name space.
The
connection to
.I exportfs
is then mounted, typically on
.BR /mnt/term .
.I Exportfs
then acts as a relay file server: operations in the imported file
tree are executed on the remote server and the results returned.  This
gives the appearance of exporting a name space from a remote machine
into a local file tree.
.PP
The 
.B -r
option bypasses the initial protocol, instead immediately
serving the namespace rooted at 
.IR root .
The
.B -s
option is equivalent to
.B -r 
.BR / ,
but predates
.B -r
and remains for compatibility.
.PP
The
.B -a
option instructs
.I exportfs
to authenticate the user, usually because it is
being invoked from a remote machine.
.PP
The
.B -F
option causes
.I exportfs
to push the
.I fcall
line discipline on its network connection.  This option is intended for networks that do not
preserve read/write boundaries.
.PP
The
.B cpu
command uses
.I exportfs
to serve device files in the terminal.  The
.IR import (4)
command calls
.I exportfs
on a remote machine, permitting users to access arbitrary pieces of
name space on other systems.
.PP
.I Srvfs
uses
.I exportfs
to create a mountable file system from a name space: a subsequent
.I mount
(see
.IR bind (1))
of
.BI /srv/ name ,
which is created with mode
.I perm
(default 0600),
will reproduce the name space rooted at
.IR dir .
One might use
.I srvfs
to enable mounting of an FTP file system (see
.IR ftpfs (4))
in several windows, or to publish a
.B /proc
(see
.IR proc (3))
with a broken process so a remote person may debug the program.
.SH SOURCE
.B /sys/src/cmd/exportfs
.br
.B /sys/src/cmd/srvfs.c