Performance graph for "Storage I/O Control Normalized Latency log" on the datastore fails to display any data.

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:

• Performance graph of "Storage I/O Control Normalized Latency log" do not display any data either real time or last day data.

For Period "Real time"  - Datastore>Monitor>Performance>Overview>Under "Select view" choose Storage I/O.

For Period "Last day" - Datastore>Monitor>Performance>Overview>Under "Select view" choose Storage I/O.

 

 

Environment

VMware vCenter Server 8.x

VMware vSphere ESXi 8.x

 

Cause

Performance graphs may not populate due to the following reasons:

• The storage I/O control is disabled on the datastores.

• The statistics logging level is not set high enough to capture the data. To populate the Storage I/O Control Normalized Latency the logging level needs to set to 3  Storage I/O Control Normalized Latency

 

Resolution

Follow the below steps to resolve this issue:

1. To Enable SIOC on the datastore.

• From the vSphere UI select Home>Inventory>Datastores
• Select a datastore that you want the charts to show actual data for.
• Select the Configuration tab.
• On the right side of the screen, select Properties for the datastore.
• Ensure that the checkbox to enable the Storage I/O control is selected in the pop-up window.
• Click Close.

2.To set the statistics collection level to 3 on vCenter UI for "Last day" data.

• In the vSphere Client interface, select Configure>General>Edit vCenter general settings" 
• Select Statistics in the pop-up window.
• Select the Statistics Interval that you want to change in the pane on the right.
• Click the Edit button.
• Select Level 3 in the Statistics Level dropdown in the pop-up window.
• Click ok.

The charts will start showing data in the real time view, as long as there is active I/O for the datastore.

Additional Information

Troubleshooting Storage I/O Control

Data Collection Levels

• When the statistics levels, level 3 or level 4 are used beyond the default value, it may cause one particular process, vpxd, to sustain memory growth, if it cannot save the statistics information to the database as quickly as required. If the usage limit of these statistics levels is not monitored closely, it may cause vpxd to grow out of memory and eventually crash.
• You can increase the Stats level to 3 for desired intervals to monitor Past Day/Week/Month data. But this is not recommended.