vmstat will report information about processes, memory, paging, block IO, traps, and cpu activity.
(this is a very busy server with ~97% CPU usage, but fortunately no swapping)
This system info can be captured over a long time with
vmstat -n 1 > vmstat.log
On Linux, CPU and memory info can be obtained with
cat /proc/cpuinfo and
cat /proc/meminfo respectively.
Top command is also a good try to identify which processes are consuming most of the server resources.
This command is used to display all the running and active real-time processes in ordered list and updates it regularly. It display CPU usage, Memory usage, Swap Memory, Cache Size, Buffer Size,Process PID, User and Commands. It also shows high memory and cpu utilisation of a running processes.
To exit from the top interface, just type q