When a VM is restarted on a new host during an HA event, how is...

All data and I/O associated with the VM are migrated to the new host.

All write I/O occurs on the new host. When reading old data, the I/O is served from the host the VM previously resided on.

All I/O continues to be served from the host the VM previously resided on.

All write I/O occurs on the new host. When reading old data, the I/O may be forwarded by the local CVM to the remote CVM.