In order to use VVols, it think I need to install VSM, correct?

Currently I'm just using MEM, no VSM. I work in a lab environment so if there is a power outage and it's longer than the ups can support, everything just powers off without warning. This has happened a couple times and all the vms seem to power back on when the power comes back.

What happens if I were using VVols though? Would certain vms just refuse to power back on because they can't find the storage due to the VSM appliance being off? Does all the traffic get passed through VSM or it's just use for  the initial connection?

Any details about how this works is appreciated.

Thanks