Keep an off-site virtual machine backup
A second copy in the same rack still shares power, cooling, and a fire. Send one copy to another site or a separate account.
Follow a simple rule: one copy on the primary backup store for fast restore, one copy off site for site loss, and the production disks themselves. The off-site copy can be asynchronous. Match its delay to how much work you can recreate.
Encrypt the copy before it leaves, and store the key somewhere that is not only inside the virtual machine you are protecting. Test a restore from the off-site copy at least once a year, because a different network path fails in different ways.
Bandwidth and immutability matter more than a second identical rack.