1.\" Copyright (c) 1989, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.Dd March 18, 2023 29.Dt MOUNTD 8 30.Os 31.Sh NAME 32.Nm mountd 33.Nd service remote 34.Tn NFS 35mount requests 36.Sh SYNOPSIS 37.Nm 38.Op Fl 2delnRrS 39.Op Fl h Ar bindip 40.Op Fl p Ar port 41.Op Ar exportsfile ... 42.Sh DESCRIPTION 43The 44.Nm 45utility is the server for 46.Tn NFS 47mount requests from other client machines. 48It listens for service requests at the port indicated in the 49.Tn NFS 50server specification; see 51.%T "Network File System Protocol Specification" , 52RFC1094, Appendix A and 53.%T "NFS: Network File System Version 3 Protocol Specification" , 54RFC1813, Appendix I. 55.Pp 56The following options are available: 57.Bl -tag -width indent 58.It Fl 2 59Allow the administrator to force clients to use only the 60version 2 61.Tn NFS 62protocol to mount file systems from this server. 63.It Fl d 64Output debugging information. 65.Nm 66will not detach from the controlling terminal and will print 67debugging messages to stderr. 68.It Fl e 69Ignored; included for backward compatibility. 70.It Fl h Ar bindip 71Specify specific IP addresses to bind to for TCP and UDP requests. 72This option may be specified multiple times. 73If no 74.Fl h 75option is specified, 76.Nm 77will bind to 78.Dv INADDR_ANY . 79Note that when specifying IP addresses with 80.Fl h , 81.Nm 82will automatically add 83.Li 127.0.0.1 84and if IPv6 is enabled, 85.Li ::1 86to the list. 87.It Fl l 88Cause all succeeded 89.Nm 90requests to be logged. 91.It Fl n 92Allow non-root mount requests to be served. 93This should only be specified if there are clients such as PC's, 94that require it. 95It will automatically clear the vfs.nfsd.nfs_privport sysctl flag, which 96controls if the kernel will accept NFS requests from reserved ports only. 97.It Fl p Ar port 98Force 99.Nm 100to bind to the specified port, for both 101.Dv AF_INET 102and 103.Dv AF_INET6 104address families. 105This is typically done to ensure that the port which 106.Nm 107binds to is a known quantity which can be used in firewall rulesets. 108If 109.Nm 110cannot bind to this port, an appropriate error will be recorded in 111the system log, and the daemon will then exit. 112.It Fl R 113Do not support the Mount protocol and do not register with 114.Xr rpcbind 8 . 115This can be done for NFSv4 only servers, since the Mount protocol is not 116used by NFSv4. 117Useful for NFSv4 only servers that do not wish to run 118.Xr rpcbind 8 . 119.Xr showmount 8 120will not work, however since NFSv4 mounts are not shown by 121.Xr showmount 8 , 122this should not be an issue for an NFSv4 only server. 123.It Fl r 124Allow mount RPCs requests for regular files to be served. 125Although this seems to violate the mount protocol specification, 126some diskless workstations do mount requests for 127their swapfiles and expect them to be regular files. 128Since a regular file cannot be specified in 129.Pa /etc/exports , 130the entire file system in which the swapfiles resides 131will have to be exported with the 132.Fl alldirs 133flag. 134.It Ar exportsfile 135Specify an alternate location 136for the exports file. 137More than one exports file can be specified. 138.It Fl S 139Tell mountd to suspend/resume execution of the nfsd threads whenever 140the exports list is being reloaded. 141This avoids intermittent access 142errors for clients that do NFS RPCs while the exports are being 143reloaded, but introduces a delay in RPC response while the reload 144is in progress. 145If 146.Nm 147crashes while an exports load is in progress, 148.Nm 149must be restarted to get the nfsd threads running again, if this 150option is used. 151.El 152.Pp 153When 154.Nm 155is started, 156it loads the export host addresses and options into the kernel 157using the 158.Xr nmount 2 159system call. 160After changing the exports file, 161a hangup signal should be sent to the 162.Nm 163daemon 164to get it to reload the export information. 165After sending the SIGHUP 166(kill \-s HUP `cat /var/run/mountd.pid`), 167check the syslog output to see if 168.Nm 169logged any parsing 170errors in the exports file. 171.Pp 172If multiple instances of 173.Nm 174are being run, either in multiple jails or both within 175and outside of a jail, care must be taken to export 176any given file system in only one of the instances. 177Note that the 178.Va allow.nfsd 179jail parameter is required to allow 180.Nm 181to run in a jail. 182See 183.Xr jail 8 184for more information. 185.Pp 186If 187.Nm 188detects that the running kernel does not include 189.Tn NFS 190support, it will attempt to load a loadable kernel module containing 191.Tn NFS 192code, using 193.Xr kldload 2 . 194If this fails, or no 195.Tn NFS 196KLD was available, 197.Nm 198exits with an error. 199When run in a jail, the 200.Xr kldload 2 201must be done outside the jail, typically by adding 202.Dq nfsd 203to 204.Va kld_list 205in the 206.Xr rc.conf 5 207file on the jail host. 208.Sh FILES 209.Bl -tag -width /var/run/mountd.pid -compact 210.It Pa /etc/exports 211the list of exported file systems 212.It Pa /var/run/mountd.pid 213the pid of the currently running mountd 214.It Pa /var/db/mountdtab 215the current list of remote mounted file systems 216.El 217.Sh SEE ALSO 218.Xr nfsstat 1 , 219.Xr kldload 2 , 220.Xr nfsv4 4 , 221.Xr exports 5 , 222.Xr rc.conf 5 , 223.Xr jail 8 , 224.Xr nfsd 8 , 225.Xr rpcbind 8 , 226.Xr showmount 8 227.Sh HISTORY 228The 229.Nm 230utility first appeared in 231.Bx 4.4 . 232