Setting Per-Second Performance Monitoring for Block Services

Prerequisites

• A storage pool has been created.
• At least two nodes in the cluster are not management nodes, control nodes, or pure compute nodes.

Context

Before per-second performance monitoring is enabled, there is limited space for storing performance monitoring data. As a result, the data can only be stored for a short period of time at a coarse granularity. After this function is enabled, performance monitoring data is written to a volume mapped to VBS nodes, so that the data is stored for a longer time at a smaller granularity.

Procedure

1. Choose Settings > Monitoring Settings > Per-Second Performance Monitoring.
2. Click Modify in the upper right corner of the page.
3. In the Per-Second Performance Monitoring area, determine whether to enable per-second performance monitoring.
   • Enabled: Performance monitoring data is written to a specified volume.
   • Disabled: Performance monitoring data will no longer be written to the volume. If you select Delete per-second performance monitoring configurations and performance data, the per-second performance monitoring data that has been saved to the volume will be deleted (unable to be restored) and can no longer be viewed. Otherwise, the data that has been saved to the volume will not be deleted.
   

   If per-second performance monitoring has never been enabled, a message will be displayed on the top of DeviceManager: "The system detects that per-second performance monitoring is not enabled. Enabling this function helps you analyze performance more accurately. Do you want to enable the function? After enablement, this prompt will be automatically cleared."

4. Select a storage pool and volume where the per-second performance monitoring data is to be stored.
   

   • A storage pool stores performance data.
   • Select or create a volume whose name prefix is PMS_SPACE_PERFORMANCE_ and volume type is Performance monitoring volume.
   • The selected volume will be formatted. Therefore, you are advised to select an empty volume (with no data).
   • The selected or newly created volume must have been mapped to 2 to 10 VBS nodes. The VBS nodes to which the volume is to be mapped cannot be management nodes, controller nodes, or pure compute nodes.
   • The volume to be selected or created must have been configured with a QoS policy.

5. In the Mount to VBS Node area, click Select.

   The Mount to VBS Node page is displayed on the right.

6. Select 2 to 10 VBS nodes to which the volume is to be mapped. They will be automatically added to the selected nodes area on the right. Then, click OK.
   

   • The selected nodes cannot be management nodes, controller nodes, or pure compute nodes. Otherwise, per-second performance monitoring will fail to be enabled. Nodes that cannot be used in per-second performance monitoring are not displayed on the Mount to VBS Node page by default. To view node roles, choose Cluster > Cluster > Hardware (management nodes and pure compute nodes) or choose Cluster > Cluster > Control Cluster (control nodes).
   • If the management IP addresses of all VBS nodes to which a volume is mounted are changed or the volume is unmapped from all VBS nodes, you need to reselect VBS nodes for mapping the volume.
   • If the management IP address of the active management node is changed, you need to reselect VBS nodes for mapping the volume.

7. Click Save.