nsswitch.conf: is there a daemon I need to restart?

Question

When I modify /etc/nsswitch.conf, is there an "nss" daemon I should restart? I am not referring to modules such as mdns & nis.

Solution 1

No you probably don't (other than what David said, and maybe ypbind, but you said not NIS). The nsswitch.conf file isn't for a daemon in particular, it is actually a file used by the C library for various system calls.

Solution 2

You may have nscd (Name Service Caching Daemon) running, which you may need to restart, otherwise it's unlikely. Certain daemons might cache get*() function call results and may need restarting.

Solution 3

Be aware that existing processes will not be aware of the changes to nsswitch.conf. The nsswitch.conf(5) page states, "Within each process that uses nsswitch.conf, the entire file is read only once; if the file is later changed, the process will continue using the old configuration."

Comments

[Kyle Brandt]

Well since my answer as accepted I have to give David the upvote :-P

[David Pashley]

\o/ cheers. now I feel the need to upvote you for your generosity.

[jldupont]

Thanks guys. I can see that nscd isn't installed/running by default on Ubuntu.

[David Pashley]

That's probably a good thing. NSCD just normally causes more problems than it solves. :)

[Ken Williams]

So what's a person to do? Reboot?

[Ron Smith]

@Ken: Sadly, this appears to be the case.

[palswim]

Rather than just restart, you could disable the thing. I would restart my NSCD and successfully resolve host names, then a short while later, my resolution would fail. This happened consistently.

[01AutoMonkey]

Installing nscd and doing sudo service nscd restart && sudo service network-manager restart removes the need to reboot for me.

[Paulo Pedroso]

Ubuntu 16: Failed to restart nscd.service: Unit nscd.service not found