Monitoring CPU usage in Ubuntu

How to find out what process is using CPU to what extent in Ubuntu? I'd like to have real-time data as well as recorded history. Both console and GUI apps would be great.

The situation is that my system seems to be really overloaded right now and I don't know why for sure. I've spent some time killing processes and watching if performance improves. And I suspect that JS Scripts running in Mozilla are causing problems. All in all a nice tool for taking a look at CPU usage would come in handy.

Solution 1:

Tried Htop ?

Solution 2:

Learn to use "sar", you'll be glad you did.

Install the "sysstat" package. It will record tons of useful system statistics, CPU, memory usage, I/O, and more. The default retention period is 7 days I believe.

Then you can go back in time for the day you want like this (for the 2nd, for example):

sar -C -f /var/log/sysstat/sa02

Solution 3:

top will give you real time data. Recorded may be more tricky.

Solution 4:

There are many tools you may use : dstat, vmstat, htop, ps ..