Shouldn't this question be on a Virtualbox forum?
I don't use VirtualBox myself, so I'm not sure how it presents the virtual hardware to the ESXi VM.
Anyway, why don't you use VMware Fusion (free for personal use) which can run ESXi VMs.
André
thank you scott, let me check
hi andre,
i am using fusion for a while now, as it is a licensed version, cannot use the free version for long. so thought of switching back to oracle virtualbox