NSCD(8)

NAME
nscd - name service caching daemon

SYNOPSIS
nscd [-dnst] [-i cachename] [-I cachename]

DESCRIPTION
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 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) and LFU (least frequently used). This type of caching is used with the getXXXbyname() 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 running nscd 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 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.

FILES
/etc/nscd.conf
    The default configuration file.

SEE ALSO
nsdispatch(3), nscd.conf(5), nsswitch.conf(5)

AUTHORS
Michael Bushkov <bushman@FreeBSD.org>

BUGS
Please send bug reports and suggestions to <bushman@FreeBSD.org>.