tools to monitor cpu usage

I would suggest: cat, crond, awk (or sed) and rrdtool.

Use cron to record into rrd database every 5 minutes ('rrdtool update'), draw nice graphs of the data for display later or in realtime (using' rrdtool graph')

### Kernel 2.6: user(normal+nice) : system : idle :iowait cat /proc/stat | awk '/cpu0 / { print $2+$3":"$4":"$5":"$6 }'

## Kernel 2.4: user(normal+nice) : system : idle : U cat /proc/stat | awk '/cpu / { print $2+$3":"$4":"$5":U" }' /devlin

You can use top from command line or grekllm