vSphere UI vSAN Services configuration page displays the error: Unable to extract requested data. Check vSphere Client logs for details

Products

• VMware vCenter Server

Issue/Introduction

• When navigating to vSAN services for the cluster on the vSphere UI encountering the below error:
  • Unable to extract requested data. Check vSphere Client logs for details
  • 
• The vsan-plugin.log contains the following entry:
  • var/log/vmware/vsphere-ui/logs/vsan-plugin.log
    • [YYYY-MM-DDTHH:MM:SS][ERROR][VC_VERSION:-BUILD_NUMBER][urn:vmomi:ClusterComputeResource:domain-##:##][com.vmware.vsan.client.h5vsanui.cluster.configure.vsan.generalConfig] ["[GLOBAL]",{"name":"TypeError","stack":"TypeError: Cannot read properties of undefined (reading 'config')\n    at K (https://vc_fqdn/plugins/com.vmware.vsan.client~8.0.203.10000~1627135819/vc_fqdn-443/vsan/plugins/vsan-ui-repa/715.js:1:3959)\n    at fh (https://vc_fqdn/plugins/com.vmware.vsan.client~8.0.203.10000~1627135819/vc_fqdn-443/vsan/plugins/vsan-ui-repa/vendor.js:1129:63105)\n    at ph  (https://vc_fqdn/plugins/com.vmware.vsan.client~8.0.203.10000~1627135819/vc_fqdn-443/vsan/plugins/vsan-ui-repa/vendor.js:1129:62293)\n    at Us (https://vc_fqdn/plugins/com.vmware.vsan.client~8.0.203.10000~1627135819/vc_fqdn-443/vsan/plugins/vsan-ui-repa/vendor.js:1129:69648)","message":"Cannot read properties of undefined (reading 'config')"}]
• Navigating to Browser > Developer Tools > Network Tab or the HAR file collected while loading the page, contains request body: PbmQueryProfile with resourceType=STORAGE, profileCategory=REQUIREMENT against ProfileManager returns storage policy uniqueIds in a single response.

Environment

VMware vCenter Server 8.x

Cause

The vCenter has an excessive number of storage policies defined.

On the vSAN General Configuration page, there is a check for datastore compatibility which issues one PbmCheckCompatibility call per policy. When the policy count is high, this exceeds the browser's concurrent-request capacity, causing requests to abort or queue with severe latency.

Resolution

• Review the generated storage policies and manually clean up unneeded storage policies to reduce the total count to a minimal number of actively required rules. Refer: Deleting a Virtual Machine Storage Policy
• Refer VMware Configuration Maximums to know the maximum number of virtual machine storage policies that needs to be configured. 

Note: Storage policies are meant to be reused for multiple objects. There are  many benefits of managing the relevant settings for the objects, when they are grouped under a single policy instead of separate ones. When there is a single storage policy, it can have a unique meaningful name that would be easy to recognize in any context and also you are able to change a setting in the storage policy and re-apply the policy to all objects that are assigned.