xref: /freebsd/usr.sbin/mountd/mountd.8 (revision 3416500aef140042c64bc149cb1ec6620483bc44)
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28.\"     @(#)mountd.8	8.4 (Berkeley) 4/28/95
29.\" $FreeBSD$
30.\"
31.Dd October 24, 2016
32.Dt MOUNTD 8
33.Os
34.Sh NAME
35.Nm mountd
36.Nd service remote
37.Tn NFS
38mount requests
39.Sh SYNOPSIS
40.Nm
41.Op Fl 2delnrS
42.Op Fl h Ar bindip
43.Op Fl p Ar port
44.Op Ar exportsfile ...
45.Sh DESCRIPTION
46The
47.Nm
48utility is the server for
49.Tn NFS
50mount requests from other client machines.
51It listens for service requests at the port indicated in the
52.Tn NFS
53server specification; see
54.%T "Network File System Protocol Specification" ,
55RFC1094, Appendix A and
56.%T "NFS: Network File System Version 3 Protocol Specification" ,
57Appendix I.
58.Pp
59The following options are available:
60.Bl -tag -width indent
61.It Fl 2
62Allow the administrator to force clients to use only the
63version 2
64.Tn NFS
65protocol to mount file systems from this server.
66.It Fl d
67Output debugging information.
68.Nm
69will not detach from the controlling terminal and will print
70debugging messages to stderr.
71.It Fl e
72Ignored; included for backward compatibility.
73.It Fl h Ar bindip
74Specify specific IP addresses to bind to for TCP and UDP requests.
75This option may be specified multiple times.
76If no
77.Fl h
78option is specified,
79.Nm
80will bind to
81.Dv INADDR_ANY .
82Note that when specifying IP addresses with
83.Fl h ,
84.Nm
85will automatically add
86.Li 127.0.0.1
87and if IPv6 is enabled,
88.Li ::1
89to the list.
90.It Fl l
91Cause all succeeded
92.Nm
93requests to be logged.
94.It Fl n
95Allow non-root mount requests to be served.
96This should only be specified if there are clients such as PC's,
97that require it.
98It will automatically clear the vfs.nfsd.nfs_privport sysctl flag, which
99controls if the kernel will accept NFS requests from reserved ports only.
100.It Fl p Ar port
101Force
102.Nm
103to bind to the specified port, for both
104.Dv AF_INET
105and
106.Dv AF_INET6
107address families.
108This is typically done to ensure that the port which
109.Nm
110binds to is a known quantity which can be used in firewall rulesets.
111If
112.Nm
113cannot bind to this port, an appropriate error will be recorded in
114the system log, and the daemon will then exit.
115.It Fl r
116Allow mount RPCs requests for regular files to be served.
117Although this seems to violate the mount protocol specification,
118some diskless workstations do mount requests for
119their swapfiles and expect them to be regular files.
120Since a regular file cannot be specified in
121.Pa /etc/exports ,
122the entire file system in which the swapfiles resides
123will have to be exported with the
124.Fl alldirs
125flag.
126.It Ar exportsfile
127Specify an alternate location
128for the exports file.
129More than one exports file can be specified.
130.It Fl S
131Tell mountd to suspend/resume execution of the nfsd threads whenever
132the exports list is being reloaded.
133This avoids intermittent access
134errors for clients that do NFS RPCs while the exports are being
135reloaded, but introduces a delay in RPC response while the reload
136is in progress.
137If
138.Nm
139crashes while an exports load is in progress,
140.Nm
141must be restarted to get the nfsd threads running again, if this
142option is used.
143.El
144.Pp
145When
146.Nm
147is started,
148it loads the export host addresses and options into the kernel
149using the
150.Xr mount 2
151system call.
152After changing the exports file,
153a hangup signal should be sent to the
154.Nm
155daemon
156to get it to reload the export information.
157After sending the SIGHUP
158(kill \-s HUP `cat /var/run/mountd.pid`),
159check the syslog output to see if
160.Nm
161logged any parsing
162errors in the exports file.
163.Pp
164If
165.Nm
166detects that the running kernel does not include
167.Tn NFS
168support, it will attempt to load a loadable kernel module containing
169.Tn NFS
170code, using
171.Xr kldload 2 .
172If this fails, or no
173.Tn NFS
174KLD was available,
175.Nm
176exits with an error.
177.Sh FILES
178.Bl -tag -width /var/run/mountd.pid -compact
179.It Pa /etc/exports
180the list of exported file systems
181.It Pa /var/run/mountd.pid
182the pid of the currently running mountd
183.It Pa /var/db/mountdtab
184the current list of remote mounted file systems
185.El
186.Sh SEE ALSO
187.Xr nfsstat 1 ,
188.Xr kldload 2 ,
189.Xr nfsv4 4 ,
190.Xr exports 5 ,
191.Xr nfsd 8 ,
192.Xr rpcbind 8 ,
193.Xr showmount 8
194.Sh HISTORY
195The
196.Nm
197utility first appeared in
198.Bx 4.4 .
199