Online monitoring window features


Online monitoring window features
Prev	Real-time statistics collection and display	Next

The Online Monitoring window displays real-time statistics for storage objects you select. It can include disks, subdisks, and volumes. To access the Online Monitoring window, select Statistics>Online Monitoring from the Tools menu, then select the storage objects to monitor in a preliminary window that comes up, and click OK.

The Online Monitoring window collects statistics as long as you have it open. The window can operate in the background. You can do other commands while the window is open. When you set up the real-time statistics, you can change the refresh rate, the time interval of the refresh of the screen display. The default is 5 seconds. The statistics are computed continuously in the background.

The Online Monitoring window is organized as follows:

Name

The first column contains the names of the storage objects that have been selected for monitoring. Thus, each row contains the statistical data on a selected storage object.
Hot Spot

The second column has a pie symbol that is designed to be used as an indicator for hot spot detection. A hot spot is an area of high I/O activity that may cause bottlenecks in I/O throughput. The color and shading of each pie symbol indicate the current state of I/O activity for the associated storage object. The pie symbol for the highest amount of I/O activity, Critical activity, is red and fully shaded, making it easy to notice on the screen. You can select the statistical parameters you want to use for hot spot detection.
Statistical Parameters

The remaining columns represent the different statistical parameters available in the program. By default, Read Requests per Second, Write Requests per Second, Read and Write Requests per Second, Read and Write Blocks per Second, and Queue Depth are selected, but you can select any of the nine statistical parameters.
Legend for the Hot Spot Indicator

The legend at the bottom of the window describes the four pie symbol categories for the hot spot indicator. The table below gives more detail on these categories. If the pie symbol indicator displays the High or Critical category, it signals the fact that you have a hot spot - that is, an area of high I/O activity.

Table: Explanation of the pie symbol categories for hot spot indicator

I/O Activity	Pie Symbol	Subdisk I/O	Dynamic Disk I/O
Low	Blue Small section in pie	Does not apply	More than 30% below average if it is not below minimum I/O threshold
Normal	Green Section less than half of pie	80% or less of parent disk I/O	30% below average up to 30% above average
High	Yellow Section more than half of pie	81% to 90% of parent disk I/O	31% to 50% above average
Critical	Red Color in all of pie	More than 90% of parent disk I/O	More than 50% above average

Context Menu
If you right-click any row in the Online Monitoring window, a context menu appears with the following two menu choices relating to the storage object being monitored:
- Graph Historical Statistics Information
- Remove Object from Online Monitoring
The first menu choice is grayed out unless you have previously selected that storage object for historical statistics monitoring.