Very Computer

by **e-o-** » Wed, 04 Jul 2001 05:00:45

I all.

One question.
Is the nscd daemon necessary if I use dns and configure the nsswitch.conf
only with dns entry?
thanx.

by **Calle Dybedah** » Wed, 04 Jul 2001 18:43:12

> Is the nscd daemon necessary if I use dns and configure the nsswitch.conf
> only with dns entry?

Maybe. nscd caches many more types of data than hostnames. A trivial
way to see if you need it running is to turn it off and see if
unexpected things suddenly start running many times slower. For
example, if you have many users and turn off nscd, a simple "ps -fe"
will take _ages_ to complete.
--

by **Matthew SA** » Wed, 04 Jul 2001 23:27:36

>Is the nscd daemon necessary if I use dns and configure
>the nsswitch.conf only with dns entry?

To not use nscd for dns caching do the following:

1) edit /etc/nscd.conf to not enable hosts caching:
enable-cache hosts no

2) restart nscd
/etc/init.d/nscd stop
/etc/init.d/nscd start

nscd is also used for caching other databases such as passwd and group.
If you have a large number of users, nscd can be pretty handy.

The comp.unix.solaris faq at
ftp://rtfm.mit.edu/pub/usenet-by-hierarchy/comp/unix/solaris
has more information on nscd and nsswitch.conf.

-Matthew

by **Dirk Kiehn** » Thu, 05 Jul 2001 06:39:54

> >Is the nscd daemon necessary if I use dns and configure
> >the nsswitch.conf only with dns entry?

> To not use nscd for dns caching do the following:

> 1) edit /etc/nscd.conf to not enable hosts caching:
> enable-cache hosts no

> 2) restart nscd
> /etc/init.d/nscd stop
> /etc/init.d/nscd start

> nscd is also used for caching other databases such as passwd and group.
> If you have a large number of users, nscd can be pretty handy.

> The comp.unix.solaris faq at
> ftp://rtfm.mit.edu/pub/usenet-by-hierarchy/comp/unix/solaris
> has more information on nscd and nsswitch.conf.

> -Matthew

My Sun version of nscd works fine because of a parameter in the
nscd.conf file:

old-data-ok hosts no

But my SuSE Linux machine doesn't allow this parameter in its config
file and hence I get problems when addresses change, like they did
at Yahoo some months ago.

My current workaround is to just kill nscd on Linux, but if I could
just clean the cache out I'm sure things would be OK. My problem is
that I can't find this cache. The config file doesn't say where it
is located nor did a semi thorough search find it. The man pages for
Solaris don't say where it is and there isn't one for Linux.

I'm upgrading to Susue 7.1 soon, but I'd still like to know where the
cache is located. Does anone here know??

-Dirk

by **Richard L. Hamilt** » Fri, 06 Jul 2001 03:42:17

>> >Is the nscd daemon necessary if I use dns and configure
>> >the nsswitch.conf only with dns entry?

>> To not use nscd for dns caching do the following:

>> 1) edit /etc/nscd.conf to not enable hosts caching:
>> enable-cache hosts no

>> 2) restart nscd
>> /etc/init.d/nscd stop
>> /etc/init.d/nscd start

>> nscd is also used for caching other databases such as passwd and group.
>> If you have a large number of users, nscd can be pretty handy.

>> The comp.unix.solaris faq at
>> ftp://rtfm.mit.edu/pub/usenet-by-hierarchy/comp/unix/solaris
>> has more information on nscd and nsswitch.conf.

>> -Matthew

> My Sun version of nscd works fine because of a parameter in the
> nscd.conf file:

> old-data-ok hosts no

> But my SuSE Linux machine doesn't allow this parameter in its config
> file and hence I get problems when addresses change, like they did
> at Yahoo some months ago.

> My current workaround is to just kill nscd on Linux, but if I could
> just clean the cache out I'm sure things would be OK. My problem is
> that I can't find this cache. The config file doesn't say where it
> is located nor did a semi thorough search find it. The man pages for
> Solaris don't say where it is and there isn't one for Linux.

> I'm upgrading to Susue 7.1 soon, but I'd still like to know where the
> cache is located. Does anone here know??

I didn't even know that Linux had nscd.

On Solaris, one can flush a particular cache (as root) with

# nscd -i hosts
(or whatever name; on Solaris 8 and later, you may want to flush
ipnodes and hosts together)

The cache (Solaris, anyway) is almost certainly not a file at all,
but rather in the memory of the nscd process itself. I just wish
there was an option to dump the cache contents for a particular
name; it might help to determine where a bogus value came from if
one could readily find out what the bogus value _was_.

--
ftp> get |fortune
377 I/O error: smart remark generator failed

Bogonics: the primary language inside the Beltway

by **Dirk Kiehn** » Sat, 07 Jul 2001 10:47:25

> >> >Is the nscd daemon necessary if I use dns and configure
> >> >the nsswitch.conf only with dns entry?

> >> To not use nscd for dns caching do the following:

> >> 1) edit /etc/nscd.conf to not enable hosts caching:
> >> enable-cache hosts no

> >> 2) restart nscd
> >> /etc/init.d/nscd stop
> >> /etc/init.d/nscd start

> >> nscd is also used for caching other databases such as passwd and group.
> >> If you have a large number of users, nscd can be pretty handy.

> >> The comp.unix.solaris faq at
> >> ftp://rtfm.mit.edu/pub/usenet-by-hierarchy/comp/unix/solaris
> >> has more information on nscd and nsswitch.conf.

> >> -Matthew

> > My Sun version of nscd works fine because of a parameter in the
> > nscd.conf file:

> > old-data-ok hosts no

> > But my SuSE Linux machine doesn't allow this parameter in its config
> > file and hence I get problems when addresses change, like they did
> > at Yahoo some months ago.

> > My current workaround is to just kill nscd on Linux, but if I could
> > just clean the cache out I'm sure things would be OK. My problem is
> > that I can't find this cache. The config file doesn't say where it
> > is located nor did a semi thorough search find it. The man pages for
> > Solaris don't say where it is and there isn't one for Linux.

> > I'm upgrading to Susue 7.1 soon, but I'd still like to know where the
> > cache is located. Does anone here know??

> I didn't even know that Linux had nscd.

> On Solaris, one can flush a particular cache (as root) with

> # nscd -i hosts
> (or whatever name; on Solaris 8 and later, you may want to flush
> ipnodes and hosts together)

> The cache (Solaris, anyway) is almost certainly not a file at all,
> but rather in the memory of the nscd process itself. I just wish
> there was an option to dump the cache contents for a particular
> name; it might help to determine where a bogus value came from if
> one could readily find out what the bogus value _was_.

> --
> ftp> get |fortune
> 377 I/O error: smart remark generator failed

> Bogonics: the primary language inside the Beltway

Thanks for the info...I tried the same on Suse and got:
/root# nscd -i hosts
nscd: invalid option -- i
Try `nscd --help' or `nscd --usage' for more information.

So, still hoping:

Usage: nscd [OPTION...]
Name Service Cache Daemon.

-d, --debug Do not fork and display messages on the
current
tty
-f, --config-file=NAME Read configuration data from NAME
-g, --statistic Print current configuration statistic
-K, --shutdown Shut the server down
-S, --secure=TABLE,yes Use separate cache for each user
-t, --nthreads=NUMBER Start NUMBER threads
-?, --help Give this help list
--usage Give a short usage message
-V, --version Print program version

Mandatory or optional arguments to long options are also mandatory or
optional
for any corresponding short options.

Doesn't look like it's there...but I'll take a look at some of the flags
to see if I can get ahead there. In any case 7.1 goes on my system
tomorrow.

Thanks again,
-Dirk