VCF brownfield precheck Enhanced Linked Mode failure

Products

• VMware SDDC Manager

Issue/Introduction

Running the vcf_brownfield.py script after doing a domain repoint on vCenter to break Enhanced Linked Mode (ELM) yields in a ELM precheck failure. 

Environment

VCF 5.x

Cause

The domain repoint command changed the LDU value of the vCenter incorrectly leading to an ELM precheck failure.

Resolution

This will be addressed in a future vCenter patch. A manual workaround to correct the LDU is available.

1. Take the proper snapshots of all vCenters
   • VMware vCenter in Enhanced Linked Mode pre-changes snapshot (online or offline) best practice
2. SSH into the vCenter and obtain correct LDU value using the following command
   
/usr/lib/vmware-vmafd/bin/vmafd-cli get-ldu --server-name localhost
   
   
3. Run the following multiline command
   
   /opt/likewise/bin/ldapmodify -x -D cn=Administrator,cn=Users,dc=vsphere,dc=local -W <<EOF
dn: cn=node_a.example.com,ou=Domain Controllers,dc=vsphere,dc=local
changetype: modify
replace: vmwLDUGuid
vmwLDUGuid: LDU-GUID-from-step-1
EOF
   
   Note: Replace the text in red with your environment details, for example, replace "node_a.example.com" with the FQDN of the vCenter.
   
   
4. Re-run precheck script.