How can I force a system reboot every night (logged in as admin NOT root)? I tried making a script: su mypassword reboot and calling crontab to every night.. but it still prompts me for a password?

Put the job in the crontab for root. 0 4 0 0 0 shutdown -y -i 6 Does your machine need to be rebooted every night? Sounds like something is wrong. Reboots are for system upgrades. Most unix boxes are happy with uptime measured in years.

But the cron job isn't fireing if i'm not logged in as root? I need to know how to call shutdown from a normal user because now all i get is presmission denied errors.

Cron does not depend on a user to be logged in. Have you tried it? Are there not already scheduled tasks that run as root? Having said that, if you create a script owned by root with the set uid bit set, the script will execute as root, no matter who actually starts it. << DANGER - BAD IDEA #!/bin/sh shutdown -i 6 -y

yep your right, all i was missing was /sbin/shutdown it wasn't getting called unless i but the sbin in front

This is why many people either declare the PATH variable for cron scripts or use full path names to executables. Cron run in a severely limited shell. You can add the verbose tracing to a script by putting 'set -x' near the top. That would show you what it is trying to do.