vCenter server upgrade from 6.x to 7.x stuck at 0% in Stage-2 while "Copy data from source vCenter Server to target vCenter Server" phase.

Products

• VMware vCenter Server 7.0
• VMware vCenter Server 8.0
• VMware vCenter Server

Issue/Introduction

• In stage 2, the upgrade process does not progress at the beginning phase "Copy data from source vCenter Server to target vCenter Server" 
• The vCenter Server is pointed to HA LB VIP as Platform Service Controller (PSC).
• In prechecks.json on the target vCenter Server, you can see an entry similar to: 
  
  

   "error": [
  {
        "text": {
          "id": "ur.replication.partner.error.text",
          "translatable": "The provided replication partner '%(0)s' is not found in the connected vCenter Server list.",
          "args": [
            "<FQDN_of_LB>"
          ],
          "localized": "The provided replication partner '<FQDN of LB>' is not found in the connected vCenter Server list."
        },
        "description": null,
        "resolution": {
          "id": "ur.replication.partner.error.resolution",
          "translatable": "Select the replication partner from the discovered connected vCenter Server(s) - %(0)s.",
          "args": [
            "<FQDN _OF_PSC1>, <FQDN _OF_PSC2>"
          ],
          "localized": "Select the replication partner from the discovered connected vCenter Server(s) -<FQDN _OF_PSC1>, <FQDN_OF_PSC2>"
        },
        "problemId": null
      }
    ],

Cause

This is a known behavior in upgrading vCenter Server when PSC HA LB VIP is configured as PSC of the source vCenter Server.

Resolution

Workaround:

This can be resolved by unconfiguring PSC HA and repointing vCenter server to the one of a member of PSC HA.

1. Getting safe snapshots PSCs and vCenter Server with power-off state
2. Unconfiguring PSC HA on All PSC nodes by a command "lsdoctor.py -p" (Refer to Using the 'lsdoctor' Tool )
3. Repointing vCenter Server to the one of PSCs by a command "cmsso-util repoint" (Refer to How to repoint vCenter Server 6.x between External PSC within a site )
4. Unregister the other PSC from the above PSC by a command "cmsso-util unregister" (Refer to Using the cmsso command to unregister vCenter with External PSC or vCenter with Embedded PSC from Single Sign-On )
5. Retry the upgrade