FileVault 2 is a great way to encrypt your entire disk. In case your Macs gets stolen or lost, you have piece of mind that all the data is safe and can not be accessed by anyone else. 

On a Mac Server though, whole-disk encryption is not really practical. This is because it requires a manual password entry every time you restart the server. As the Mac mini is in a remote datacenter, this is not possible. 

Also, your server is likely to be switched on all the time, so your disk will be unencrypted while online.

We do NOT recommend to switch FileVault on for your whole disk. It will make your server to go offline and we need to go to the data center and manually enter the password, which you need to share with us. 

We do understand that you might have sensitive data and want to protect it by using encryption. This is of course still possible via alternative ways. To store sensitive data, you can for example: