Crontab -e yields: /var/spool/cron/: mkstemp: Permission denied

cron

I'm trying to set up a cron job under my user. I run crontab -e, make my edits, and try to save and exit. I receive the following error message /var/spool/cron/: mkstemp: Permission denied.

Relevant output from ls -al /var/spool/cron/crontabs

drwxr-xr-x 2 root crontab 4096 Nov  4 10:09 .
drwxr-xr-x 5 root root    4096 Nov 19  2014 ..
-rw-rw-rw- 1 greg crontab   91 Nov  4 11:04 greg
-rw------- 1 root crontab 1231 Oct 29 16:18 root

I can directly edit the greg file and save that but I still can't seem to get the job to run, even if I restart cron after updating it. What do I need to do to fix this problem?

The output from ls -lha $(which crontab) is:

-rwxr-sr-x 1 root crontab 36K Feb  8  2013 /usr/bin/crontab

The output from groups greg is:

greg : greg adm sudo crontab lpadmin sambashare

Best Answer

This will fix your immediate problem:

chmod u=rwx,g=wx,o=t /var/spool/cron/crontabs

But, if you can download packages, a more robust way to fix this is to use apt-get to reinstall the appropriate package:

root@ubuntu# dpkg-query -S /var/spool/cron/crontabs
cron: /var/spool/cron/crontabs
root@ubuntu# apt-get install --reinstall cron

after first making sure any local changes you've made to /etc/init/cron.conf, /etc/default/cron, etc. are copied somewhere and then reapplied.

Related Solutions

Cron – Differences Between /etc/crontab, /etc/cron.d/, and /var/spool/cron/crontabs/root

/etc/crontab is the historical location for "system" jobs. It's not necessarily used on all systems (eg RedHat 7 and derivatives has an "empty" entry), or it may have commands to call out to cron.daily and others.

/etc/cron.d/* is, essentially, the same as /etc/crontab but split out into separate files. This makes it easy for packages to add new cron entries; just put them in this directory.

So, for example, on CentOS 7:

% rpm -ql sysstat | grep cron
/etc/cron.d/sysstat

% sudo cat /etc/cron.d/sysstat
# Run system activity accounting tool every 10 minutes
*/10 * * * * root /usr/lib64/sa/sa1 1 1
# 0 * * * * root /usr/lib64/sa/sa1 600 6 &
# Generate a daily summary of process accounting at 23:53
53 23 * * * root /usr/lib64/sa/sa2 -A

You can see these entries match what would otherwise be in /etc/crontab.

Before the cron.d was designed, a script would need to edit /etc/crontab to do the same work, which is more hard work, and likely to go wrong.

/var/spool/cron/crontabs is the stuff managed by the crontab command.

So...

If a cron job is to be deployed by a package then the package should put the file into /etc/cron.d/. Enterprise automation tools may also do that.

If a sysadmin (or any other user) wants to add a cron job with crontab -e then it will be put into /var/spool/cron/crontabs/

Best Answer

Related Solutions

Cron – Differences Between /etc/crontab, /etc/cron.d/, and /var/spool/cron/crontabs/root

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