Upgrade to M-Files Online Subscription

Hi All,

I would like to know what are the things that need to be considered when switching from M-Files perpetual to M-Files Online Subscription (Professional edition to be exact).
Note: This is not conversion from old to new one, this is acquiring for a new license. 

Is it required a vault migration, new server, user settings, configurations, etc.?
Is there any technical documentation available so we can prepare before to go on M-Files Online Subscription.