1NSCD(8) Linux Programmer's Manual NSCD(8)
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6 /usr/sbin/nscd - name service cache daemon
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9 Nscd is a daemon that provides a cache for the most common name service
10 requests. The default configuration file, /etc/nscd.conf, determines
11 the behavior of the cache daemon. See nscd.conf(5).
12 Nscd provides caching for accesses of the passwd(5), group(5), and
14 hosts(5) databases through standard libc interfaces, such as getpw‐
15 nam(3), getpwuid(3), getgrnam(3), getgrgid(3), gethostbyname(3), and
16 others.
17 There are two caches for each database: a positive one for items found,
19 and a negative one for items not found. Each cache has a separate TTL
20 (time-to-live) period for its data. Note that the shadow file is
21 specifically not cached. getspnam(3) calls remain uncached as a
22 result. As a result of this behavior it is not possible to change non-
23 nscd user to another non-nscd user via su service when nscd is running.
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26 --help will give you a list with all options and what they do.
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29 The daemon will try to watch for changes in configuration files appro‐
30 priate for each database (e.g. /etc/passwd for the passwd database or
31 /etc/hosts and /etc/resolv.conf for the hosts database), and flush the
32 cache when these are changed. However, this will happen only after a
33 short delay (unless the inotify(7) mechanism is available and glibc 2.9
34 or later is available), and this auto-detection does not cover configu‐
35 ration files required by nonstandard NSS modules, if any are specified
36 in /etc/nsswitch.conf. In that case, you need to run the following
37 command after changing the configuration file of the database so that
38 nscd invalidates its cache:
39 $ nscd -i <database>
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43 nscd.conf(5), nsswitch.conf(5)
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46 This page is part of release 3.25 of the Linux man-pages project. A
47 description of the project, and information about reporting bugs, can
48 be found at http://www.kernel.org/doc/man-pages/.
49GNU 2008-12-05 NSCD(8)