The following subsections describe the four processing methods provided by Real Time SAN Replication to mirror data from the main site to the remote site. The system configuration and the operating procedures differ depending on the method used to mirror data, so the HiRDB administrator must choose the method that best suits the local system environment. The following are the four methods:

• All synchronous method
• All asynchronous method
• Hybrid method
• Log-only synchronous method