NFSUSERD(8)             FreeBSD System Manager's Manual            NFSUSERD(8)

NAME
     nfsuserd - load user and group information into the kernel for NFSv4
     services plus support manage-gids for all NFS versions

SYNOPSIS
     nfsuserd [-domain domain_name] [-usertimeout minutes]
              [-usermax max_cache_size] [-verbose] [-force] [-manage-gids]
              [num_servers]

DESCRIPTION
     nfsuserd loads user and group information into the kernel for NFSv4.  For
     Kerberized NFSv4 mounts, it must be running on both client(s) and server
     for correct operation.  For non-Kerberized NFSv4 mounts, this daemon must
     be running unless all client(s) plus the server are configured to put
     uid/gid numbers in the owner and owner_group strings.

     It also provides support for manage-gids and must be running on the
     server if this is being used for any version of NFS.

     Upon startup, it loads the machines DNS domain name, plus timeout and
     cache size limit into the kernel.  It then preloads the cache with group
     and user information, up to the cache size limit and forks off N children
     (default 4), that service requests from the kernel for cache misses.  The
     master server is there for the sole purpose of killing off the slaves.
     To stop the nfsuserd, send a SIGUSR1 to the master server.

     The following options are available:

     -domain domain_name
             This option allows you to override the default DNS domain name,
             which is acquired by taking either the suffix on the machine's
             hostname or, if that name is not a fully qualified host name, the
             canonical name as reported by getaddrinfo(3).

     -usertimeout minutes
             Overrides the default timeout for cache entries, in minutes.  The
             longer the time out, the better the performance, but the longer
             it takes for replaced entries to be seen.  If your user/group
             database management system almost never re-uses the same names or
             id numbers, a large timeout is recommended.  The default is 1
             minute.

     -usermax max_cache_size
             Overrides the default upper bound on the cache size.  The larger
             the cache, the more kernel memory is used, but the better the
             performance.  If your system can afford the memory use, make this
             the sum of the number of entries in your group and password
             databases.  The default is 200 entries.

     -verbose
             When set, the server logs a bunch of information to syslog.

     -force  This flag option must be set to restart the daemon after it has
             gone away abnormally and refuses to start, because it thinks
             nfsuserd is already running.

     -manage-gids
             This flag enables manage-gids for the NFS server nfsd(8).  When
             this is enabled, all NFS requests using AUTH_SYS authentication
             take the uid from the RPC request and uses the group list for
             that uid provided by getgrouplist(3) on the server instead of the
             list of groups provided in the RPC authenticator.  This can be
             used to avoid the 16 group limit for AUTH_SYS.

     num_servers
             Specifies how many servers to create (max 20).  The default of 4
             may be sufficient.  You should run enough servers, so that ps(1)
             shows almost no running time for one or two of the slaves after
             the system has been running for a long period.  Running too few
             will have a major performance impact, whereas running too many
             will only tie up some resources, such as a process table entry
             and swap space.

SEE ALSO
     getgrent(3), getgrouplist(3), getpwent(3), nfsv4(4), group(5), passwd(5),
     nfsd(8)

HISTORY
     The nfsuserd utility was introduced with the NFSv4 experimental subsystem
     in 2009.

BUGS
     The nfsuserd use getgrent(3), getgrouplist(3) and getpwent(3) library
     calls to resolve requests and will hang if the servers handling those
     requests fail and the library functions don't return.  See group(5) and
     passwd(5) for more information on how the databases are accessed.

FreeBSD 13.1-RELEASE-p6          April 6, 2019         FreeBSD 13.1-RELEASE-p6