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-   -   Can I disable at daemon or is it used by system processes? (https://www.linuxquestions.org/questions/slackware-14/can-i-disable-at-daemon-or-is-it-used-by-system-processes-4175529293/)

kairen 12-26-2014 02:47 PM
Can I disable at daemon or is it used by system processes?
 
Hi,

I am trying to learn more about my Slackware distro and right now I am looking at the output of ps ax command.

There is one line saying

Code:
855 ?        Ss    0:00 /usr/sbin/atd -b 15 -l 1
Google said atd is a daemon for scheduling tasks. I run atq and nothing was found.

My question is can I disable at from running? How can I check if some system processes are using it?

Code:
uname -a
Linux ErikDT 3.10.17 #2 SMP Wed Oct 23 16:34:38 CDT 2013 x86_64 Intel(R) Core(TM) i7 CPU      Q 740  @ 1.73GHz GenuineIntel GNU/Linux
Slackware version is Slackware64 14.1

Thanks.

justwantin 12-26-2014 04:50 PM
If you do not intend to use the command at you can prevent that from being called at start up by commenting out the relevant line in /etc/rc.d/rc.M.
However, on this Salix-14.1 box, it makes no use of cpu or memory unless called specificaly.
Code:
rick[~]$ ps -A | grep atd
  792 ?        00:00:00 atd
rick[~]$ ps -p 792 -o %cpu,%mem
%CPU %MEM
 0.0  0.0
Nor on a Pi running slackwarearm-current.
Code:
rick@shed-1:~$ ps -A | grep atd
  536 ?        00:00:00 atd
rick@shed-1:~$ ps -p 536 -o %cpu,%mem
%CPU %MEM
 0.0  0.0
You could also be lazy and just chmod the atd command so it is not executable. It is found in in /usr/sbin.
Code:
rick[~]$ ps -p 792 -o %cpu,%mem,cmd
%CPU %MEM CMD
 0.0  0.0 /usr/sbin/atd -b 15 -l 1
Cheers!

kairen 12-26-2014 04:54 PM
You say I need to keep "at" in order to use crond? Are they not separate daemons?

justwantin 12-26-2014 05:00 PM
No I mistakenly discuused the use of at and cron as they both were used for scheduling. crond does not need at.

My apologies, I have edited my post to avoid confusion

kairen 12-26-2014 05:06 PM
Thanks, for your time and answer.

So you think "at" is not used by system processes on a clean Slackware64 installation and can be safely removed?

justwantin 12-26-2014 05:17 PM
I do not know if there is anything else in a default install that uses at. There may or may not be and of course you may install something in the future that requires it and you'd never know because it would be assumed that at would be installed and hence not listed as a dependency. Its really up to you whether you choose to use it. I wouldn't bother to uninstall it.

I have two DVB-T cards in this box and the script I use to save TV shows uses at to schedule when the save begins.

frankbell 12-26-2014 06:42 PM
For any daemon or process, you should be able to view the appropriate man page to find out what it does. It would at least be a place to start in determining whether or not you want to turn it off.

For a daemon, such as "atd," you'd look and "man at," for example.

No ss process is running on this Slackware box, but "man ss" tells me what it's for.

kairen 12-27-2014 01:34 AM
frankbell, I read the man page before asking my question. My particular interest was not in at itself but in any processes that might (by default) be using it. Thank you for your time.

justwantin, thanks for the advice and time.

I am marking this as SOLVED.


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