* %nice: Nice time. This represents the percentage of time during the sample interval that CPUs were servicing processes in which their priority had been lowered-in effect, they have been nice to other processes. This time counts as CPU utilization and can be also considered user mode time. Oracle systems tend to have zero nice time.

The total idle time is the sum of %iowait, %steal, and %idle time. Referring to Figure 4-8, the CPU subsystem is utilized around 20% to 30%, so the CPU subsystem is idle between 70% to 80% of the time. It appears there is plenty of CPU power available.

All Linux/Unix systems contain the /proc virtual file system, which offers a staggering amount of information about operating system activity: CPU, memory, device and IO activity, process-level information, and even CPU chip details. It's amazing what you can find. For most DBA types, /proc represents a whole new world to explore! On Linux, all the /proc files are in text, and they can be easily retrieved and parsed to create your own reports. Unfortunately, on other platforms, such as HP-UX and Solaris, the /proc files are binary, and you'll need to do some work, such as write a C program, to retrieve the details.