xref: /freebsd/usr.sbin/nfsuserd/nfsuserd.8 (revision 43faedc1339a9624c7acedb7f3e5624e64da5b99)
1.\" Copyright (c) 2009 Rick Macklem, University of Guelph
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25.\" $FreeBSD$
26.\"
27.Dd November 1, 2015
28.Dt NFSUSERD 8
29.Os
30.Sh NAME
31.Nm nfsuserd
32.Nd load user and group information into the kernel for
33.Tn NFSv4
34services plus support manage-gids for all NFS versions
35.Sh SYNOPSIS
36.Nm nfsuserd
37.Op Fl domain Ar domain_name
38.Op Fl usertimeout Ar minutes
39.Op Fl usermax Ar max_cache_size
40.Op Fl verbose
41.Op Fl force
42.Op Fl manage-gids
43.Op Ar num_servers
44.Sh DESCRIPTION
45.Nm
46loads user and group information into the kernel for NFSv4.
47It must be running for NFSv4 to function correctly, either client or server.
48It also provides support for manage-gids and must be running on the server if
49this is being used for any version of NFS.
50.Pp
51Upon startup, it loads the machines DNS domain name, plus timeout and
52cache size limit into the kernel. It then preloads the cache with group
53and user information, up to the cache size limit and forks off N children
54(default 4), that service requests from the kernel for cache misses. The
55master server is there for the sole purpose of killing off the slaves.
56To stop the nfsuserd, send a SIGUSR1 to the master server.
57.Pp
58The following options are available:
59.Bl -tag -width Ds
60.It Fl domain Ar domain_name
61This option allows you to override the default DNS domain name, which
62is acquired by taking either the suffix on the machine's hostname or,
63if that name is not a fully qualified host name, the canonical name as
64reported by
65.Xr getaddrinfo 3 .
66.It Fl usertimeout Ar minutes
67Overrides the default timeout for cache entries, in minutes. If the
68timeout is specified as 0, cache entries never time out. The longer the
69time out, the better the performance, but the longer it takes for replaced
70entries to be seen. If your user/group database management system almost
71never re-uses the same names or id numbers, a large timeout is recommended.
72The default is 1 minute.
73.It Fl usermax Ar max_cache_size
74Overrides the default upper bound on the cache size. The larger the cache,
75the more kernel memory is used, but the better the performance. If your
76system can afford the memory use, make this the sum of the number of
77entries in your group and password databases.
78The default is 200 entries.
79.It Fl verbose
80When set, the server logs a bunch of information to syslog.
81.It Fl force
82This flag option must be set to restart the daemon after it has gone away
83abnormally and refuses to start, because it thinks nfsuserd is already
84running.
85.It Fl manage-gids
86This flag enables manage-gids for the NFS server
87.Xr nfsd 8 .
88When this is enabled, all NFS requests using
89AUTH_SYS authentication take the uid from the RPC request
90and uses the group list for that uid provided by
91.Xr getgrouplist 3
92on the server instead of the list of groups provided in the RPC authenticator.
93This can be used to avoid the 16 group limit for AUTH_SYS.
94.It Ar num_servers
95Specifies how many servers to create (max 20).
96The default of 4 may be sufficient. You should run enough servers, so that
97.Xr ps 1
98shows almost no running time for one or two of the slaves after the system
99has been running for a long period. Running too few will have a major
100performance impact, whereas running too many will only tie up some resources,
101such as a process table entry and swap space.
102.El
103.Sh SEE ALSO
104.Xr getgrent 3 ,
105.Xr getgrouplist 3 ,
106.Xr getpwent 3 ,
107.Xr nfsv4 4 ,
108.Xr group 5 ,
109.Xr passwd 5 ,
110.Xr nfsd 8
111.Sh HISTORY
112The
113.Nm
114utility was introduced with the NFSv4 experimental subsystem in 2009.
115.Sh BUGS
116The
117.Nm
118use
119.Xr getgrent 3 ,
120.Xr getgrouplist 3
121and
122.Xr getpwent 3
123library calls to resolve requests and will hang if the servers handling
124those requests fail and the library functions don't return. See
125.Xr group 5
126and
127.Xr passwd 5
128for more information on how the databases are accessed.
129