Free open source softwares are available for managing and monitoring, processes, files, directories and filesystems on a UNIX system. These softwares can conducts automatic maintenance and repair and can execute meaningful causal actions in error situations.
If you are looking for support then do let us know.
Few of the tools are:
bsign - Corruption & intrusion detection using embedded hashes
systraq - monitor your system and warn when system files change
tripwire - file and directory integrity checker
mon - monitor hosts/services/whatever and alert about problems
monit - A utility for monitoring and managing daemons or similar programs
iotop - simple top-like I/O monitor
ipband - daemon for subnet bandwidth monitoring with reporting via email
iptotal - monitor for IP traffic, not requiring SNMP
itop - simple top-like interrupt load monitor
iwatch - realtime filesystem monitoring program using inotify
kboincspy - monitoring utility for the BOINC client
kismet - Wireless 802.11b monitoring tool
hobbit - monitoring system for systems, networks and applications - server
hobbit-client - client for the Hobbit network monitor
hobbit-plugins - plugins for the Hobbit network monitor
nagios3 - A host/service/network monitoring and management system
munin - network-wide graphing framework (grapher/gatherer)
gamin - File and directory monitoring system
iptraf - Interactive Colorful IP LAN Monitor
mdadm - tool to administer Linux MD arrays (software RAID)
smartmontools - control and monitor storage systems using S.M.A.R.T.
tcpdump - A powerful tool for network monitoring and data acquisition
cacti - Frontend to rrdtool for monitoring systems and services
collectd - statistics collection and monitoring daemon
mrtg - multi router traffic grapher
mtop - MySQL terminal based query monitor
mytop - top like query monitor for MySQL
ptop - PostgreSQL performance monitoring tool akin to top
tcpspy - Incoming and Outgoing TCP/IP connections logger
tcpstat - network interface statistics reporting tool
tcpwatch-httpproxy - TCP monitoring and logging tool with support for HTTP 1.1
tenshi - log monitoring and reporting tool
