ip_conntrack problem: error: "net.ipv4.ip_conntrack_max" is an unknown key

To fix this issue do the following:

1. modprobe ip_conntrack
2. lsmod |grep conn -- if you see entries it means modules have been loaded correctly
3. sysctl -w -- to write the changes you made under /etc/sysctl.conf
4. sysctl -p -- to view the changes and see if it was actually loaded.

Command to check CronJobs

There are times that you need to immediately check if there are run-away cron entries hidden somewhere. This terminal command will save you time doing just that.


for user in $(cut -f1 -d: /etc/passwd); do crontab -u $user -l; done

Now, if for example you need to issue this remotely you can do it like this:


ssh someusername@some_remote_host sudo for user in $(cut -f1 -d: /etc/passwd); do crontab -u $user -l; done

Enjoy!