Definition
DRaaS replaces a self-managed secondary site with a cloud-hosted recovery environment, often built on infrastructure like IBM Power Virtual Server, that a provider keeps ready and bills for on a subscription basis. Some approaches keep a minimally resourced cloud instance inactive until it is actually needed for failover, which lowers ongoing cost compared to running a fully provisioned standby system year-round.
For IBM i buyers, DRaaS is usually evaluated alongside traditional HA and backup options rather than as a complete replacement for them, since recovery point and recovery time objectives still drive which combination of tools makes sense.