nscd.conf - configuration file for Name Service Caching Daemon
/etc/nscd.conf configures the caches used by nscd(8)
as well as some generic options. nscd(8) 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)'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
- logfile file
- Specifies the name of the debug log-file that nscd(8) should use if
debug-level is higher than 0. If this option is not set,
nscd(8) will write its debug output to stderr.
- debug-level level
- If level is higher than 0, nscd(8) 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) should use by
default. It can be overridden by calling nscd(8) with the -t
or --nthreads argument. If neither this configuration option nor
the command line argument is given, nscd(8) uses 5 threads by
default. The minimum is 3. More threads means more simultaneous
connections that nscd(8) can handle.
- max-threads #threads
- Specifies the maximum number of threads to be started.
- server-user user
- By default, nscd(8) is run as user root. This option can be set to
force nscd(8) to drop root privileges after startup. It cannot be
used when nscd(8) 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) 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.
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) 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) 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) 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) 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.
# 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