Services

[Mike A. Harris]

On Wed, 15 Oct 2003, Mattias Dahlberg wrote:

>There have been many discussions on how to make the startup faster. One of
>the easiest ways is to turn off any services that you don't need. In regard
>to this I wonder about some services that are started by default (even in
>the Personal Desktop setup) and whether it would be possible to detect if
>the user really needs them or not.
>
>Two examples: pcmcia and isdn. Because pcmcia has always been started by
>default (even on non-laptops) I presume there's no reliable way to detect
>if the computer has pcmcia slots or not? How about isdn, maybe it could be
>included only if a modem has been detected?
>
>Other services that are on by default: nfslock, sendmail and sshd. Any way
>it could be detected if the user actually needs these? When I installed

[root at devel root]# /usr/bin/time service isdn start
0.01user 0.00system 0:00.02elapsed 96%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (942major+322minor)pagefaults 0swaps

Saving 0.02 seconds during boot time isn't worth the effort for 
isdn at least.  I don't have the pcmcia package installed to test 
that.

IMHO, before considering spending any time at all on improving
something strictly for performance benefits, one needs to 
evaluate if there is any significant performance loss to begin 
with.  In the case of the isdn script above, I do not have ISDN 
service, nor is it configured, which will be the state for the 
majority of users out there.  Losing 0.02 seconds during boot 
time is not a significant loss to care about.  If it took 2 
seconds, then it would be worth investigation mind you.

>Fedora Core test3 nfs wasn't started, but nfslock was. Maybe sshd could be
>added only if OpenSSH has been configured?

How exactly?  I'm not sure that makes any sense.  On a fresh OS 
installation, I expect to be able to ssh to that machine over the 
network, and to do so without editing any ssh config files.  I 
don't mind if I have to personally run ntsysv and turn "sshd" on 
and start the service the first time, but editing config files is 
not something I want to _have_ to do in order to run an ssh 
server.  It should work out-of-box in a general sense without 
configuration, and our existing default works well.

The client side and server side of ssh are entirely isolated and 
wether one is planning on using the client or the server, neither 
should be installed or configured based upon the other.

Not exactly sure what you're suggesting here...  configure what 
exactly?


-- 
Mike A. Harris     ftp://people.redhat.com/mharris
OS Systems Engineer - XFree86 maintainer - Red Hat