NSCD(8) BSD System Manager's Manual NSCD(8)NAMEnscd — name service caching daemon
SYNOPSISnscd [-dnst] [-i cachename] [-I cachename]
The nscd utility is the system caching daemon. It can cache almost all
types of data and is basically intended to be used with the nsswitch sub‐
system. The cache is actually per-user. This means that each user can
work only with the cached data that were cached by themselves, and cannot
poison the cache of other users. The nscd utility supports two types of
Each cached element is the key+value pair. This type of caching
supports policies which are applied when maximum number of cached
elements is exceeded. Three policies are available: FIFO (first in
- first out), LRU (least recently used) and LFU (least frequently
used). This type of caching is used with the getXXXbyname() family
Each cached element is the part of the elements sequence. This
type of caching is intended to be used with the getXXXent() family
The nscd utility is able not only to cache elements, but to perform the
actual nsswitch lookups by itself. To enable this feature, use the
perform-actual-lookups parameter in nscd.conf(5).
The nscd utility recognizes the following runtime options:
-n Do not daemonize; nscd will not fork or disconnect itself from
-s Single-threaded mode. Forces using only one thread for all pro‐
cessing purposes (it overrides the threads parameter in the
-t Trace mode. All trace messages will be written to stdout. This
mode is usually used with -n and -s flags are used for debugging
Invalidates personal cache. When specified, nscd acts as the
administration tool. It asks the already running nscd to invali‐
date the specified part of the cache of the calling user. For
example, sometimes you may want to invalidate your “hosts” cache.
You can specify “all” as the cachename to invalidate your per‐
sonal cache as a whole. You cannot use this option for the
cachename for which the perform-actual-lookups option is enabled.
Invalidates the cache for every user. When specified, nscd acts
as the administration tool. It asks the already running nscd to
invalidate the specified part of the cache for every user. You
can specify “all” as the cachename to invalidate the whole cache.
Only the root can use this option.
/etc/nscd.conf The default configuration file.
SEE ALSOnsdispatch(3), nscd.conf(5), nsswitch.conf(5)AUTHORS
Michael Bushkov ⟨firstname.lastname@example.org⟩
Please send bug reports and suggestions to ⟨email@example.com⟩.
BSD October 20, 2005 BSD