The document describes different disaster recovery methodologies including hot site, warm site, and cold site options that can be provided on demand from a private cloud or traditionally with physical infrastructure. An on-demand hot site provides the shortest RPO of 30 minutes and RTO of 1 hour by keeping application and database servers ready in a private cloud. An on-demand warm site has an RPO of 2 hours and RTO of 4 hours by maintaining operating systems and applications ready. An on-demand cold site has an RPO of 6 hours and RTO of 24 hours by backing up to an online storage service.