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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.  It
     must be running for NFSv4 to function correctly, either client or server.
     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 data-
	     bases.  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.

     Since the kernel communicates with	the nfsuserd daemon via	an upcall that
     uses the IP address 127.0.0.1, it does not	work correctly when jail(8)
     are used and can crash the	system.

FreeBSD	11.2			 July 4, 2017			  FreeBSD 11.2

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | HISTORY | BUGS

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