While I was waiting for advice I have done some testing for this and found the story is a little bit different in live system. Here is some behavior I observed, hopefully it could be helpful for someone who is interested in this topic.
I built a new RHEL 7.5 VM and tried a couple of methods to migrate the VM across two hosts in ESXi 7 environment, and here is the finding:
- Scenario 1: Direct Migration – Cold (Power-off VM)
- uuid.bios remains as it is
- vc.uuid remains as it is
- Provisioning network connection is required between two datacenters or hosts
- Low BW is bearable
- Scenario 2: Direct Migration – Hot (vMotion, live migration without downtime, however I can’t test it due to lab network limitation
- Assuming both uuid.bios and vc.uuid remain unchanged as cold migration case
- Provisioning & vMotion network connections are required between two hosts
- Min. 1Gbps link is required across datacentres or hosts and 10Gbps is recommended.
- Scenario 3: Export/Import VM with default setting
- uuid.bios changed to a new one
- vc.bios changed to a new one
- no network connection required between two hosts
- Scenario 4: Export/Import VM with advanced setting (this is new to me but there are options to include BIOS UUID and MAC address)
- uuid.bios remains as it is
- vc.bios changed to a new one
- no network connection required between two hosts
- Scenario 5: Backup/Restoration
- uuid.bios changed to a new one
- vc.bios changed to a new one
- no network connection required between two hosts
so I guess with the migration there will be no drama on UUID if it's possible, otherwise it might be required to manipulate the UUID manually by editing vmx file.