Hello and welcome to LQ. Hope you like it here.
Every night between 11-3AM, our FC5 box locks up
So, what processes run during that time? Does running SAR (sa, atsar, atop, dstat) or the system and daemon logs show any "weirdness" leading up or during that time?
We have had multiple failed logins in our logs of people trying to Telnet or SSH in. Could these hack attempts be the problem?
How did you investigate those attempts? What where the results? What did you implement to stop these attempts?