I have a test VMware box with one 8GB USB flash drive and one 1 TB HD on LSI Raid Controller. I installed ESXi V4.1 on USB flash drive and created three VMs on 1TB HD. Then I proceeded to upgrade ESX. After putting ESXi V5.1 in CD-ROM, I rebooted the host. I am stuck at the screen where I have to choose the Disk to install or Upgrade (Please see three screenshots). I think I need to select 8GB USB flash drive because that is where I installed ESXi V4.1. When I chose USB, then I have to select one of the two options on the next screen. Am I right, at least, when I choose USB flash drive?
On the next screen with USB option, do I choose Install or Force Migrate?
What are the differences between these two choices?