I can run cron jobs manually like this
root@myhosting [~]# sync ; echo 0 > /proc/sys/vm/drop_caches
I can add it in to cPanel like this. This doesnt work because I need root access.
* */4 * * * sync; echo 0 > /proc/sys/vm/drop_caches
So that leaves me to add the job using putty logged in as root. The above code doesn't work in putty. I get command not found