Our primary hyper-v host is running 2008 and I plan to upgrade it to 2012 R2. My question is regarding the guests. I don't mind the downtime over a weekend, so I don't plan on setting up a temporary server. The guests are on a separate raid, can I re-install the os/host then point them to the guest vm's or do I have to do an export/import of each one? Pretty sure I know the answer is do an export/import, but that adds a lot of downtime, since I'm only rebuilding the host.