MOUNTD(8) FreeBSD System Manager's Manual MOUNTD(8)
NAME
mountd - service remote NFS mount requests
SYNOPSIS
mountd [-2AadelNnRrSs] [-h bindip] [-p port] [exportsfile ...]
DESCRIPTION
The mountd utility is the server for NFS mount requests from other client
machines. It listens for service requests at the port indicated in the
NFS server specification; see Network File System Protocol Specification,
RFC1094, Appendix A and NFS: Network File System Version 3 Protocol
Specification, RFC1813, Appendix I.
The following options are available:
-2 Allow the administrator to force clients to use only the version
2 NFS protocol to mount file systems from this server.
-A Silence the warnings related to "administrative controls". These
warnings remind users that an exported "administrative control"
directory that is not a local server file system mount point
actually exports the entire local file system and not just the
subtree below the directory exported. (See exports(5))
-a Enforce the check for an exported directory being a file system
mount point, if the --alldirs option is specified in exports(5)
for the export file line. With this option, the exports line
will fail, whereas without this option, a warning will be
generated by syslog(8), but the export will be done.
-d Output debugging information. mountd will not detach from the
controlling terminal and will print debugging messages to stderr.
-e Ignored; included for backward compatibility.
-h bindip
Specify specific IP addresses to bind to for TCP and UDP
requests. This option may be specified multiple times. If no -h
option is specified, mountd will bind to INADDR_ANY. Note that
when specifying IP addresses with -h, mountd will automatically
add 127.0.0.1 and if IPv6 is enabled, ::1 to the list.
-l Cause all succeeded mountd requests to be logged.
-N Cause mountd to execute in the foreground instead of in daemon
mode.
-n Allow non-root mount requests to be served. This should only be
specified if there are clients such as PC's, that require it. It
will automatically clear the vfs.nfsd.nfs_privport sysctl flag,
which controls if the kernel will accept NFS requests from
reserved ports only.
-p port
Force mountd to bind to the specified port, for both AF_INET and
AF_INET6 address families. This is typically done to ensure that
the port which mountd binds to is a known quantity which can be
used in firewall rulesets. If mountd cannot bind to this port,
an appropriate error will be recorded in the system log, and the
daemon will then exit.
-R Do not support the Mount protocol and do not register with
rpcbind(8). This can be done for NFSv4 only servers, since the
Mount protocol is not used by NFSv4. Useful for NFSv4 only
servers that do not wish to run rpcbind(8). showmount(8) will
not work, however since NFSv4 mounts are not shown by
showmount(8), this should not be an issue for an NFSv4 only
server.
-r Allow mount RPCs requests for regular files to be served.
Although this seems to violate the mount protocol specification,
some diskless workstations do mount requests for their swapfiles
and expect them to be regular files. Since a regular file cannot
be specified in /etc/exports, the entire file system in which the
swapfiles resides will have to be exported with the -alldirs
flag.
exportsfile
Specify an alternate location for the exports file. More than
one exports file can be specified.
-S Tell mountd to suspend/resume execution of the nfsd threads
whenever the exports list is being reloaded. This avoids
intermittent access errors for clients that do NFS RPCs while the
exports are being reloaded, but introduces a delay in RPC
response while the reload is in progress. If mountd crashes
while an exports load is in progress, mountd must be restarted to
get the nfsd threads running again, if this option is used.
-s Cause mountd to skip automatic binding to localhost for IPv4 and
IPv6. This option is meaningless unless -h has also been used.
When mountd is started, it loads the export host addresses and options
into the kernel using the nmount(2) system call. After changing the
exports file, a hangup signal should be sent to the mountd daemon to get
it to reload the export information. After sending the SIGHUP (kill -s
HUP `cat /var/run/mountd.pid`), check the syslog output to see if mountd
logged any parsing errors in the exports file.
If multiple instances of mountd are being run, either in multiple jails
or both within and outside of a jail, care must be taken to export any
given file system in only one of the instances. Note that the allow.nfsd
jail parameter is required to allow mountd to run in a jail. See jail(8)
for more information.
If mountd detects that the running kernel does not include NFS support,
it will attempt to load a loadable kernel module containing NFS code,
using kldload(2). If this fails, or no NFS KLD was available, mountd
exits with an error. When run in a jail, the kldload(2) must be done
outside the jail, typically by adding "nfsd" to kld_list in the
rc.conf(5) file on the jail host.
FILES
/etc/exports the list of exported file systems
/var/run/mountd.pid the pid of the currently running mountd
/var/db/mountdtab the current list of remote mounted file systems
SEE ALSO
nfsstat(1), kldload(2), nfsv4(4), exports(5), rc.conf(5), jail(8),
nfsd(8), rpcbind(8), showmount(8), syslog(8)
HISTORY
The mountd utility first appeared in 4.4BSD.
FreeBSD 15.1-STABLE-HBSD December 16, 2024 MOUNTD(8)