--- name: "nscd.conf" section: "5" platform: "linux" package: "nscd" version: "2.41-12+deb13u4" release: "Debian 13 (Trixie)" platforms: ["linux", "freebsd"] url: "https://new.carta.tech/nscd.conf" --- # nscd.conf(5) configuration file for Name Service Caching Daemon ## NAME nscd.conf - configuration file for Name Service Caching Daemon ## DESCRIPTION */etc/nscd.conf* configures the caches used by [**nscd**(8)](/nscd/8.md) as well as some generic options. [**nscd**(8)](/nscd/8.md) is able to use a configuration file at a different location, when supplied with the *-f* or *--config-file* command line option. The configuration file consists of a set of lines. Empty lines, and text after a '#' is ignored. All remaining lines denote the setting of an option. White space before and after options, and between options and option arguments is ignored. There are two kinds of options: General options influence [**nscd**(8)](/nscd/8.md)'s general behaviour, while cache related options only affect the specified cache. Options are set like this: ``` general_option option cache_option cache_name option ``` ## GENERAL OPTIONS - **logfile** *file* Specifies the name of the debug log-file that [**nscd**(8)](/nscd/8.md) should use if **debug-level** is higher than **0**. If this option is not set, [**nscd**(8)](/nscd/8.md) will write its debug output to stderr. - **debug-level** *level* If *level* is higher than **0**, [**nscd**(8)](/nscd/8.md) will create some debug output. The higher the level, the more verbose the output. - **threads** *#threads* This option sets the number of threads that [**nscd**(8)](/nscd/8.md) should use by default. It can be overridden by calling [**nscd**(8)](/nscd/8.md) with the *-t* or *--nthreads* argument. If neither this configuration option nor the command line argument is given, [**nscd**(8)](/nscd/8.md) uses 5 threads by default. The minimum is 3. More threads means more simultaneous connections that [**nscd**(8)](/nscd/8.md) can handle. - **max-threads** *#threads* Specifies the maximum number of threads to be started. - **server-user** *user* By default, [**nscd**(8)](/nscd/8.md) is run as user root. This option can be set to force [**nscd**(8)](/nscd/8.md) to drop root privileges after startup. It cannot be used when [**nscd**(8)](/nscd/8.md) is called with the *-S* or *--secure* argument. Also note that some services require that nscd run as root, so using this may break those lookup services. - **stat-user** *user* Specifies the user who is allowed to request statistics. - **paranoia** *bool* *bool* must be one of **yes** or **no**. Enabling paranoia mode causes [**nscd**(8)](/nscd/8.md) to restart itself periodically. - **restart-interval** *time* Sets the restart interval to time seconds if periodic restart is enabled by enabling paranoia mode. The default value is 3600. ## CACHE OPTIONS All cache options take two arguments. The first one denotes the service or cache the option should affect. Currently *service* can be one of **passwd**, **group**, or **hosts**. - **enable-cache** *service bool* *bool* must be one of **yes** or **no**. Each cache is disabled by default and must be enabled explicitly by setting this options to **yes**. - **positive-time-to-live** *service secs* This is the number of seconds after which a cached entry is removed from the cache. This defaults to 3600 seconds (i. e. one hour). - **negative-time-to-live** *service secs* If an entry is not found by the Name Service, it is added to the cache and marked as "not existent". This option sets the number of seconds after which such a not existent entry is removed from the cache. This defaults to 20 seconds for the **password** and **host** caches and to 60 seconds for the **group** cache. - **suggested-size** *service prime-number* This option sets the size of the hash that is used to store the cache entries. As this is a hash, it should be reasonably larger than the maximum number of entries that is expected to be cached simultaneously and should be a prime number. It defaults to a size of 211 entries. - **check-files** *service bool* *bool* must be one of **yes** (default) or **no**. If file checking is enabled, [**nscd**(8)](/nscd/8.md) periodically checks the modification time of */etc/passwd*, */etc/group*, or */etc/hosts* (for the **passwd**, **group**, and **host** cache respectively) and invalidates the cache if the file has changed since the last check. - **persistent** *service bool* *bool* must be one of **yes** (default) or **no**. Keep the content of the cache for service over [**nscd**(8)](/nscd/8.md) restarts. Useful when paranoia mode is set. - **shared** *service bool* *bool* must be one of **yes** (default) or **no**. The memory mapping of the [**nscd**(8)](/nscd/8.md) databases for service is shared with the clients so that they can directly search in them instead of having to ask the daemon over the socket each time a lookup is performed. - **reload-count** *#number* Sets the number of times a cached record is reloaded before it is pruned from the cache. Each cache record has a timeout, when that timeout expires, [**nscd**(8)](/nscd/8.md) will either reload it (query the NSS service again if the data hasn't changed), or drop it. - **max-db-size** *service number-of-bytes* Sets the maximum allowable size for the service. - **auto-propagate** *service bool* When set to no for passwd or group service, then the *.byname* requests are not added to *passwd.byuid* or *group.bygid* cache. This may help for tables containing multiple records for the same id. ## EXAMPLE ``` # This is a comment. logfile /var/log/nscd.log threads 6 server-user nobody debug-level 0 enable-cache passwd yes positive-time-to-live passwd 600 negative-time-to-live passwd 20 suggested-size passwd 211 check-files passwd yes enable-cache group yes positive-time-to-live group 3600 negative-time-to-live group 60 suggested-size group 211 check-files group yes enable-cache hosts yes positive-time-to-live hosts 3600 negative-time-to-live hosts 20 suggested-size hosts 211 check-files hosts yes ``` ## SEE ALSO [nscd(8)](/nscd/8.md), [nsswitch.conf(5)](/nsswitch.conf/5.md)