NFSUSERD(8) BSD System Manager's Manual NFSUSERD(8)NAMEnfsuserd — load user and group information into the kernel for NFSv4 ser‐
vices
SYNOPSISnfsuserd [-domain domain_name] [-usertimeout minutes]
[-usermax max_cache_size] [-verbose] [-force] [num_servers]
DESCRIPTIONnfsuserd loads user and group information into the kernel for NFSv4. It
must be running for NFSv4 to function correctly, either client or server.
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
cannonical name as reported by getaddrinfo(3).
-usertimeout minutes
Overrides the default timeout for cache entries, in minutes. If
the timeout is specified as 0, cache entries never time out. 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.
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 ALSOgetpwent(3), getgrent(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) 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.
BSD April 25, 2009 BSD
