topic Re: NSCD in Operating System - Linux

NSCD

Karthik S S — Tue, 16 Dec 2003 17:35:20 GMT

What is the significance of NSCD and how do I enable it.

I did the following,

chkconfig nscd on
nscd

But nscd -g reports that it is not running nor does ps -ef|grep nscd

Pl. help

Thanks,
Karthik S S

Re: NSCD

James A. Donovan — Tue, 16 Dec 2003 17:40:18 GMT

nscd is the name server caching daemon.

$ man 8 nscd

DESCRIPTION
Nscd is a daemon that provides a cache for the most common
name service requests. The default configuration file
/etc/nscd.conf determines the behavior of the cache daeÂ
mon. See nscd.conf(5).

Nscd provides cacheing for the passwd(5), group(5) and
hosts(5) databases through standard libc interfaces, such
as getpwnam(3), getpwuid(3), getgrnam(3), getgrgid(3),
gethostbyname(3) and others. Each cache has a separate TTL
(time-to-live) for its data; modifying the local database
( /etc/passwd, and so forth) causes that the cache becomes
invalidated within fifteen seconds. Note that the shadow
file is specifically not cached. getspnam(3) calls remain
uncached as a resul

Re: NSCD

Huc_1 — Tue, 16 Dec 2003 18:27:46 GMT

Karthik,

As root an
#service nscd start
should start this service

Other valid parameters to service 'something' are (help, status, ...)

you should perhaps pass it to the level you need it to run at with

chkconfig --level 345 nscd

(this would run it at level 3, 4, and 5)

I would run this only on a buzy system, so the info is keept on specific cache to speed things up

Hope this is what you needed ?

J-P

Re: NSCD

Stuart Browne — Tue, 16 Dec 2003 18:30:41 GMT

It caches both names, usernames, group entries, and other common lookup details.

As was mentioned in one mail-list thread of SuSE's (http://lists.suse.com/archive/suse-linux-e/2000-Feb/0686.html).

It seems that it's of most use in two cases:

1) When the password, group, and other core files (not shadow) are large (50-100k+), or

2) When the password, group, and other core files are on a remote server.

This just allows for the details to be cached locally in RAM for faster acces to such details, rather than having to go fetch them for every request.

Now,a s to why it's not running, have you tried 'service nscd start' instead of just 'nscd' on it's own? Have you also verified that '/etc/nscd.conf' has realistic values in it?

I've attached the 'nscd.conf' from my RH box here, and it seems to work just fine.

Just a note, I've never used this daemon. I guess I'm in too small of an environment to have any need.. ;)

Re: NSCD

Karthik S S — Tue, 16 Dec 2003 18:30:57 GMT

Yeah thanks a lot.

A simple reboot solved my problem.

Thanks,
Karthik S S