Help for System Usage Status


Description of the information displayed

The System Usage Status page displays the current CPU usage and disk access statistics.

CPU Usage Information

The CPU usage information provides data on where the system is spending its time processing requests. It divides the system processing time into four states (described below) and shows the amount of time spent in each state since the system was started. The times shown are in hundredths of a second (0.01)

State Description
User mode Time spent performing application processing (non-kernel functions)
User mode low Time spent performing low priority application processing, which would be preempted if a higher priority task was scheduled
System mode Time spent performing kernel functions such as I/O and hardware interrupt processing
Idle task Amount of time the CPU was available for work


Disk Access Information

The disk access information displays the number and type of disk accesses made since the system was started.

Access Type Description
Disk Total number of disk I/O requests processed
Disk read I/O Number of I/O requests processed to read data from the disk
Disk write I/O Number of I/O requests processed to write data to the disk
Disk read block Number of times the kernel processed a request to read data from the disk, which results in the kernel reading cached data or performing a disk I/O operation to obtain the data
Disk write block Number of times the kernel processed a request to write a block of data to the disk, which results in the kernel either immediately performing an I/O operation to store the data on disk or caching the data and updating the disk later.



Description of the buttons and actions available

refresh Click this button to display the current CPU usage and disk access statistics.
history Click this button to display the list of historical entries containing CPU usage and disk access statistics, allowing you to display a prior snapshot of the information.