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).
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13 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.
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18 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 non-standard 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:
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40 $ 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 3.22 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/.
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52GNU 2008-12-05 NSCD(8)