NSCD(8) BSD System Manager's Manual 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 ele-
ments 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>.
BSD October 20, 2005 BSD
Check Out this Related Man Page
nscd(1M) System Administration Commands nscd(1M)NAME
nscd - name service cache daemon
SYNOPSIS
/usr/sbin/nscd [-f configuration-file] [-g] [-e cachename, yes | no] [-i cachename]
DESCRIPTION
nscd is a process that provides a cache for the most common name service requests. The default configuration-file /etc/nscd.conf determines
the behavior of the cache daemon. See nscd.conf(4).
nscd provides caching for the passwd(4), group(4), hosts(4), ipnodes(4), exec_attr(4), prof_attr(4), and user_attr(4) databases through
standard libc interfaces, such as gethostbyname(3NSL), getipnodebyname(3SOCKET), gethostbyaddr(3NSL), and others. Each cache has a separate
time-to-live for its data; modifying the local database (/etc/hosts, /etc/resolv.conf, and so forth) causes that cache to become invali-
dated upon the next call to nscd. The shadow file is specifically not cached. getspnam(3C) calls remain uncached as a result.
nscd also acts as its own administration tool. If an instance of nscd is already running, commands are passed to the running version trans-
parently.
In order to preserve NIS+ security, the nscd service checks the permissions on the passwd table if NIS+ is being used. If this table cannot
be read by unauthenticated users, then nscd will make sure that any encrypted password information returned from the NIS+ server is sup-
plied only to the owner of that password.
OPTIONS
Several of the options described below require a cachename specification. Supported values are passwd, group, hosts, ipnodes, exec_attr,
prof_attr, and user_attr.
-f configuration-file Causes nscd to read its configuration data from the specified file.
-g Prints current configuration and statistics to standard output. This is the only option executable by non-root
users.
-e cachename, yes|no Enables or disables the specified cache.
-i cachename Invalidate the specified cache.
EXAMPLES
Example 1: Stopping and restarting the nscd daemon.
example# svcadm disable system/name-service-cache
example# svcadm enable system/name-service-cache
FILES
/etc/nscd.conf Determines athe behavior of the cache daemon
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO svcs(1), svcadm(1M), getspnam(3C), gethostbyname(3NSL), getipnodebyname(3SOCKET), exec_attr(4), group(4), hosts(4), ipnodes(4),
nscd.conf(4), nsswitch.conf(4), passwd(4), prof_attr(4), user_attr(4), attributes(5),
NOTES
The output from the -g option to nscd is subject to change. Do not rely upon it as a programming interface.
The nscd service is managed by the service management facility, smf(5), under the service identifier:
svc:/system/name-service-cache
Administrative actions on this service, such as enabling, disabling, or requesting restart, can be performed using svcadm(1M). The ser-
vice's status can be queried using the svcs(1) command.
SunOS 5.10 30 Oct 2003 nscd(1M)