Performance data and statistics collection

Performance monitoring and analysis are very important for high-performing systems such as IBM FlashSystem 820 and IBM SAN Volume Controller. In most cases when using this bundle, there is sufficient performance data provided by SVC and monitored by IBM Tivoli Productivity Center. However, for precise performance tuning and identification of bottlenecks, statistics from the IBM FlashSystem 820 should be collected and analyzed too.

There are two methods of performance monitoring in IBM FlashSystem 820:

򐂰 Using command-line interface (CLI) for current data

򐂰 Using graphical user interface (GUI) for current and historical data

For information about how to access the IBM FlashSystem 820 by GUI and CLI, refer to 4.1, “Setup and configuration of IBM FlashSystem for use with SAN Volume Controller” on page 78.

Using the CLI to access current data

Performance statistics management can be done by using stats command. See Example 3-2.

Example 3-2 Output of stats command

admin #: stats

Valid sub-commands are: view

info log

This command allows three options (subcommands):

򐂰 the view subcommand is used to read specific system component and statistic name combinations. Multiple combinations can be viewed at a time. The statistic values are refreshed once every second

򐂰 the info subcommand is used to view all system components with statistics available, as well as each statistic that is available for specific system components.

򐂰 the log subcommand is used to display information about statistics logging or to update the logged statistics list. Issuing the stats log command without arguments will display the current logged statistics.

The format of the stats command is the following:

stats view [<system_component> <statistic_name>]

To view the list of available components with statistics, use the stats info command. See Example 3-3 for reference:

Example 3-3 List of the components with statistics available

admin #: stats info

The following system components have statistics available: bus SuperEnv SystemEnvA SystemEnvB mcp-1 mcp-2 flashcard-1 flashcard-2 flashcard-3 flashcard-4 flashcard-5 flashcard-6 flashcard-7 flashcard-8 flashcard-9 flashcard-10 flashcard-11 flashcard-12 fc-1 fc-1a fc-1b fc-2 fc-2a fc-2b

For each component, a list of statistics is available. Use the stats info [component_name]

command. See Example 3-4:

Example 3-4 List of the statistics that are available for the component “flashcard-1”

admin #: stats info flashcard-1

The following statistics are available for the 'flashcard-1' system component: Statistic Name --- Description

temperature temperature

onboard.cap_sense_stat (onboard) cap_sense_stat onboard.cap_vin_stat (onboard) cap_vin_stat onboard.cap_adin_stat (onboard) cap_adin_stat onboard.fpgas_per_board (onboard) fpgas_per_board onboard.fpgas_in_chain (onboard) fpgas_in_chain onboard.cs_per_lane (onboard) cs_per_lane

onboard.presented_size_align8 (onboard) presented_size_align8 onboard.presented_size_max8 (onboard) presented_size_max8 onboard.temperature (onboard) temperature

onboard.health_state (onboard) health_state onboard.overall_health (onboard) overall_health onboard.available_remap (onboard) available_remap onboard.block_wear_max (onboard) block_wear_max onboard.block_wear_min (onboard) block_wear_min

onboard.block_wear_avg (onboard) block_wear_avg onboard.available_brp (onboard) available_brp

Example 3-5 shows the usage of the stats command to get the statistics of a specific component.

Example 3-5 Output of the component statistics

admin #: stats view system iops system iops --- 2030.00 2100.00 1990.00 1270.00

The statistics update time is one second.

To obtain the list of the statistics logs that are available, use the stats log command. See Example 3-6 for reference.

Example 3-6 Log files that are available on the system

admin #: stats log Logged Statistics:

Object---Name---Description--- system bw Bandwidth

system idle_cpu CPU Idle system iops IOs per second

system iowait_cpu CPU IO Wait Utilization system irq_cpu CPU Hard IRQ Utilization system nice_cpu CPU Nice Utilization system rb_bw_avg Average Rebuild BW system softirq_cpu CPU Soft IRQ Utilization system system_cpu CPU System Utilization system temperature Max System Temperature system user_cpu CPU User Utilization

Log files present on the system can be obtained through the GUI. See “Using the GUI to access current and historical data” for reference. Statistics monitoring using CLI is intended for monitoring current data for a short time while doing performance tuning or while identifying a bottleneck. To obtain statistics for a specific period, scripting methods can be used.

Using the GUI to access current and historical data

The GUI provides a more convenient way to monitor and gather performance data. It is possible to monitor current activity, as well as retrieve historical data stored in the log files. Figure 3-5 on page 73 shows the initial view of the performance monitoring tool in the IBM FlashSystem 820 GUI.

Figure 3-5 Overall view of the performance statistics option in IBM FlashSystem 820 GUI

This view allows you to monitor the current statistics and save the momentary values to a text file for future usage. You can also make a window capture of the current statistics graphs and save it to a JPG file. To do that, select Snapshot and Save on the window menu accordingly.

To add a system component statistic to monitor, use the Add button of the window menu. See Figure 3-6.

Figure 3-6 Add statistics dialog of the performance monitoring tool

Using this dialog, it is possible to add several components and component statistics at a time. The selected statistics are presented in different colors on the graph. This is shown in Figure 3-7 on page 74.

Figure 3-7 Statistics values represented on the graph

Color and scale can be adjusted for each value by using the Configure tab of the menu. The interval for statistics collection can be selected in the Configure dialog, as well. See

Figure 3-8.

Figure 3-8 Configure dialog of the performance tool

To view historical performance data, use the History tab of the Statistics tab of the main management menu. This tab opens the list of the available statistics in log files, which can be viewed or saved. It is possible to perform multiple selections and combine several graphs in one to compare different values for better performance analysis. See Figure 3-9 on page 75.

Figure 3-9 Historical statistics log files to view multiple selections

Select Save/View on the top menu to view selected statistics on the same graph for analysis and comparison. See Figure 3-10.

Figure 3-10 Graph with multiple statistics for analysis