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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. 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 terminating 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 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.
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 14.0-RELEASE-p11 April 22, 2023 FreeBSD 14.0-RELEASE-p11