In the Warm Standby mode, there are only two data centers. The primary data center is up and running, whereas the secondary data center is turned on only when the primary data center goes down. The secondary data center is regularly backed up with primary data center's data. At times, the data is not mirrored or identical between the two data centers. On failure of the primary data center, the secondary data center replaces the primary data center. As part of disaster recovery procedure:

Warm standby mode is cost-effective in terms of data center operations. However, the application availability might defer depending on how quickly the secondary data center replaces the primary data center. The RPO and RTO for warm standby mode is less when compared to cold standby mode.