NAME
nscd
—
name service caching daemon
SYNOPSIS
nscd |
[-dnst ] [-i
cachename] [-I
cachename] |
DESCRIPTION
Thenscd
utility is the system caching daemon. It can
cache almost all types of data and is basically intended to be used with the
nsswitch
subsystem. 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 caching:
- Type
- Description
- Common caching
- 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) andLFU
(least frequently used). This type of caching is used with thegetXXXbyname
() family of functions. - Multipart caching
- Each cached element is the part of the elements sequence. This type of
caching is intended to be used with the
getXXXent
() family of functions.
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 the terminal. -s
- Single-threaded mode. Forces using only one thread for all processing purposes (it overrides the threads parameter in the nscd.conf(5) file).
-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 purposes. -i
cachename- Invalidates personal cache. When specified,
nscd
acts as the administration tool. It asks the already runningnscd
to invalidate 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 personal cache as a whole. You cannot use this option for the cachename for which the perform-actual-lookups option is enabled. -I
cachename- Invalidates the cache for every user. When specified,
nscd
acts as the administration tool. It asks the already runningnscd
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.
FILES
- /etc/nscd.conf
- The default configuration file.
SEE ALSO
AUTHORS
Michael Bushkov <bushman@freebsd.org>
BUGS
Please send bug reports and suggestions to <bushman@freebsd.org>.