enabling/disabling services during startup

[vkashesh]

hi all,
I am trying to speedup my startup time on my plug and I've been reading about the /etc/init.d directory, as well as the symblinks rcS.d and rcX.d but it is taking time to sink in.

I was hoping some of you could shed some light on this.

I have kernel 2.6.30.2 with (default installer 1.0).  I am mainly using my plug to run a program that listens on a socket and communicates with a client on that dedicated socket - nothing else.  Probably later, I will install CUPS and try to get a printing mechanism implemented but that's all.

Can anyone suggest some of the services that I can get rid of?
I am also looking for any website that explains these services...

any input will be greatly appreciated.

[Tempel]

Well, what services are being started?  Look through the various /etc/rc*.d folders for anything beginning with a capital S (those are the services being started), and tell us what they are.

Everything found in rcS.d is probably best to leave as-is, and there shouldn't be many other services starting unless you installed them in the first place.

[vkashesh]

Hi Tempel,
thanks for the reply....
Here are my directories and their content.... this is running Kernel 2.6.30.2

root@ubuntu:/etc# ls rc?.d/S*
rc0.d/S20sendsigs
rc0.d/S30urandom
rc0.d/S31umountnfs.sh
rc0.d/S35networking
rc0.d/S40umountfs
rc0.d/S48cryptdisks
rc0.d/S59cryptdisks-early
rc0.d/S60umountroot
rc0.d/S90halt
rc1.d/S30killprocs
rc1.d/S70bootlogs.sh
rc1.d/S90single
rc2.d/S10sysklogd
rc2.d/S11klogd
rc2.d/S16ssh
rc2.d/S70bootlogs.sh
rc2.d/S89cron
rc2.d/S99ondemand
rc2.d/S99rmnologin
rc3.d/S10sysklogd
rc3.d/S11klogd
rc3.d/S16ssh
rc3.d/S70
rc3.d/S89cron
rc3.d/S99ondemand
rc3.d/S99rmnologin
rc4.d/S10sysklogd
rc4.d/S11klogd
rc4.d/S16ssh
rc4.d/S70
rc4.d/S89cron
rc4.d/S99ondemand
rc4.d/S99rmnologin
rc5.d/S10sysklogd
rc5.d/S11klogd
rc5.d/S16ssh
rc5.d/S70bootlogs.sh
rc5.d/S89cron
rc5.d/S99ondemand
rc5.d/S99rc.local
rc5.d/S99rmnologin
rc6.d/S20sendsigs
rc6.d/S30urandom
rc6.d/S31umountnfs.sh
rc6.d/S35networking
rc6.d/S40umountfs
rc6.d/S48cryptdisks
rc6.d/S59cryptdisks-early
rc6.d/S60umountroot
rc6.d/S90reboot

[Tempel]

Most of those look like important system services (logging, cron), that you might be able to mess with if you're feeling brave, but I wouldn't recommend it.  SSH is optional, but I'm guessing that's how you're connecting to your plug, so can't get rid of that.

The only exception is "ondemand"; I'm not sure what that is (and it doesn't appear in the Debian install I have on mine).  Okay, a quick search tells me it does CPU frequency scaling, which you maybe don't want if you're going for the best performance.  But you should find out more about it first.

If you want to learn more about any of the services being started, you just need to find out what package they belong to.  Just use "dpkg -S" on the script in the init folder and it will tell you (eg. "dpkg -S /etc/init.d/ondemand").  Then use "aptitude show" to get more information about that package (eg. "aptitude show initscripts").

Oh yeah, and if you're going for the fastest possible boot, there's only so much you can do by fiddling with system services.  If you want to get faster, you're going to need some deep magic that is well beyond me.