Wow. This thread has been created 6 years ago. And they still haven't implemented any sort of failsafe, raid in case things go wrong.
My VPS just went down yesterday. After a 5-6 hours downtime, they just sent me an email saying that unfortunately due to hardware failure, they had to create a new VPS for me, same IP, new login details will be sent via email.
And of course. This is a completely new, empty VPS. So all my data is lost now.
I guess that answers the RAID questions.
Of course, while searching for "Vultr Raid", I couldn't find any info apart from this thread.
Meanwhile, quoting from a different VPS provider, same price:
"With regards to storage, all customer data is located on two separate RAID-secured storage backends at all times. This means that disks can fail, servers hosting those disks can malfunction and still, our customers won’t need to endure outages due to our redundancy principles."