Upgrading from Vsphere 5.1 to 6.0

Hi Guys,

Im a newbie ti VMware, only a couple of months experience.

As a test, I want to upgrade Vsphere 5.1 to 6.0 - I have 6 hosts on 2 clusters. Will upgrading Vsphere to 6.0, will it induce any down time to the VMs?

Also, the hosts are all on 5.1 i believe... upgrading to 6.0 or (6.2?) i assume that will take down the relevant host at the time?

On a final note, will I need to upgrade to VSphere 6.0, before I upgrade the hosts? ie will hosts running 5.1 be compatible with Vsphere 6.0?

Thanks for your time.

Paul