Default slackware root crontab

arubin · 03-05-2009, 06:23 AM

I have just read in slackware-basics that there is a default slackware root crontab which runs scripts in various /etc/cron directories.

Not being aware of this, I have over-written the default crontab to run my own rsync script. Presumably I have lost what might be some useful functions in the default crontab.

How can I restore the default crontab?

Thanks

allend · 03-05-2009, 06:33 AM

Reinstall the dcron package.

mRgOBLIN · 03-05-2009, 06:34 AM

Login as root and do "crontab -e" and paste this in

Code:

# If you don't want the output of a cron job mailed to you, you have to direct
# any output to /dev/null.  We'll do this here since these jobs should run
# properly on a newly installed system, but if they don't the average newbie
# might get quite perplexed about getting strange mail every 5 minutes. :^)
#
# Run the hourly, daily, weekly, and monthly cron jobs.
# Jobs that need different timing may be entered into the crontab as before,
# but most really don't need greater granularity than this.  If the exact
# times of the hourly, daily, weekly, and monthly cron jobs do not suit your
# needs, feel free to adjust them.
#
# Run hourly cron jobs at 47 minutes after the hour:
47 * * * * /usr/bin/run-parts /etc/cron.hourly 1> /dev/null
#
# Run daily cron jobs at 4:40 every day:
40 4 * * * /usr/bin/run-parts /etc/cron.daily 1> /dev/null
#
# Run weekly cron jobs at 4:30 on the first day of the week:
30 4 * * 0 /usr/bin/run-parts /etc/cron.weekly 1> /dev/null
#
# Run monthly cron jobs at 4:20 on the first day of the month:
20 4 1 * * /usr/bin/run-parts /etc/cron.monthly 1> /dev/null

Noryungi · 03-05-2009, 06:37 AM

Mount your Slackware installation CD, and re-install the package named: "dcron-2.3.3-i486-6.tgz" (in the "/a" directory) this should reinstall the default crontab as well.

If you don't want to reinstall the whole package, just do a "tar xvzf dcron-2.3.3-i486-6.tgz" in a directory (for instance in /root) and look for the correct crontab file. I can't remember if this is a separate file in the package or if this is generated by the installation procedure for the package.

Hope this helps!

GazL · 03-05-2009, 06:45 AM

One of the first changes I like to make to my system is to nice them

Code:

/usr/bin/nice -n 19 /usr/bin/run-parts /etc/cron.daily

Seems to help keep the system a little more responsive if you happen to be using it when they kick in.

Probably not a big issue if you have a strong multi-core machine, but it makes a hell of a difference on my P3-800.

arubin · 03-05-2009, 01:48 PM

Thanks all.

What I did was got hold of the package and ran explodepkg which showed that the file I wanted was called root.new.

I then ran crontab root.new

Examining the package install script showed that allend and Noryungi's suggestion would not have had the desired effect

Code:

root@LavanKossot:/home/alan/packages/temp/install# cat doinst.sh
if [ ! -r var/spool/cron/crontabs/root ]; then
  mv var/spool/cron/crontabs/root.new var/spool/cron/crontabs/root
else
  mv var/spool/cron/crontabs/root.new var/spool/cron/root.crontab.sample
fi

The file would have been created as a sample without replacing root's crontab.

The irony is that my PC is never on at 4am so I will have to do some editing.

Woodsman · 03-05-2009, 03:55 PM

Quote:

Probably not a big issue if you have a strong multi-core machine, but it makes a hell of a difference on my P3-800.

I do the same thing on my box.

I have a dual core box but I still prefer using nice as background tasks should never get in my way.

Quote:

The irony is that my PC is never on at 4am so I will have to do some editing.

Yes, the overall design philosophy is for dedicated 24/7 servers rather than desktops. So modify the cron schedule to fit your usage needs. Running cron jobs on a desktop is a tad more challenging than a 24/7 server. Some people use anachron. I wrote a shell script to do much the same:

Missed Cron Jobs

mRgOBLIN · 03-05-2009, 04:06 PM

My Desktop runs 24/7 too