Real-time performance statistics provide short-term status information for thesystem. The statistics are shown as graphs in the management GUI.
You can use system statistics to monitor the bandwidth of all the volumes, interfaces, and MDisks that are being used on your system. You can also monitor the overall CPU utilization for the system. These statistics summarize the overall performance health of the system and can be used to monitor trends in bandwidth and CPU utilization. You can monitor changes to stable values or differences between related statistics, such as the latency between volumes and MDisks. These differences then can be further evaluated by performance diagnostic tools.
Additionally, with system-level statistics, you can quickly view bandwidth of volumes, interfaces, and MDisks. Each of these graphs displays the current bandwidth in megabytes per second and a view of bandwidth over time. Each data point can be accessed to determine its individual bandwidth use and to evaluate whether a specific data point might represent performance impacts. For example, you can monitor the interfaces, such as for Fibre Channel or SAS interfaces, to determine whether the host data-transfer rate is different from the expected rate.
You can also select node-level statistics, which can help you determine the performance impact of a specific node. As with system statistics, node statistics help you to evaluate whether the node is operating within normal performance metrics.
The CPU utilization graph shows the current percentage of CPU usage and specific data points on the graph that show peaks in utilization. If compression is being used, you can monitor the amount of CPU resources that being used for compression and the amount that is available to the rest of the system.
The Interfaces graph displays data points for Fibre Channel (FC), iSCSI, serial-attached SCSI (SAS), and IP Remote Copy interfaces for both compressed and non-compressed connections. You can use this information to help determine connectivity issues that might impact performance. The Fibre Channel interface includes read and write workloads from Fibre Channel hosts and remote-copy replications from other systems.
The Volumes and MDisks graphs on the Performance panel show four metrics: Read, Write, Read latency, and Write latency. You can use these metrics to help determine the overall performance health of the volumes and MDisks on your system. Consistent unexpected results can indicate errors in configuration, system faults, or connectivity issues.
To access these performance statistics, click in the management GUI.