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

NAME
     nfsuserd  -- load user and group information into the kernel for NFSv4 ser-
     vices 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  machine's 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 num_servers
     (default 4) children which are the servers that service requests  from  the
     kernel  for cache misses.	The master is there for the sole purpose of ter-
     minating the servers.  To stop the nfsuserd, send a SIGUSR1 to the master.

     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 num-
	     bers, 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 per-
	     formance.	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 nf-
	     suserd 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 servers 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 ports 15.1		 April 22, 2023 		     NFSUSERD(8)

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