| Q: Is there a standard ratio between RTOs and RPOs, or are they independent of each other?
The RTO is the amount of time in which a system must be recovered in the event of an interruption, and the RPO is the point in time to which a system's data must be recovered. Depending on the type of application and the business function it supports, the RTO and RPO can be miles apart. An application providing a critical service relying on static data may have an RTO of one hour, but an RPO of one day. The app must be up in one hour, but using yesterday's data is OK.
It's possible to miss an RTO while trying to meet an RPO if it takes so long to restore the data to meet the RPO that the app ends up being down longer than allowed.
--Pierre Dorion, data center practice director and senior consultant, Long View Systems Inc.