Q: How do I match business disaster recovery needs and technologies?
That's really the million-dollar question. There's really a running scale for meeting those recovery point objective (RPO) or recovery time objective (RTO) objectives. The RPO can run from the ability to have zero data loss in 24 hours in a typical tape environment, to zero data loss by mirroring data synchronously. The RTO has a similar scale: How fast do you want to recover your data? These are all variables based on price.
If you don't have the experience to understand what disaster recovery technologies are available, usually the best way is to work with your trusted vendors and suppliers to help sort all that out. Really what you're trying to do is weigh out the cost of a solution versus the cost of that downtime. As your RPO and RTOs get smaller, the cost of that solution is likely to be more expensive. You want to strike that balance between what you want to be able to spend to ensure that your business can recover in a prescribed amount of time.