Nearsync replication, which provides a Recovery Point Objective (RPO) between one and fifteen minutes, has a minimum cluster size requirement. To enable and successfully configure a Nearsync schedule, the source Nutanix cluster must consist of at least three nodes. This requirement is based on the architectural design of how Nearsync manages and drains the oplog across the cluster nodes to achieve low RPOs reliably. A two-node cluster does not meet this minimum node count prerequisite, and therefore, the option to configure a Nearsync schedule will be unavailable or fail.

B. The minimum supported RPO for asynchronous replication on a two-node cluster is 60 minutes, not 15 minutes.

C. Nearsync replication is fully supported on both All-Flash and hybrid (SSD+HDD) Nutanix clusters, although performance is best on All-Flash.

D. A Witness VM is required for quorum and metadata management in a two-node cluster, but it does not enable Nearsync replication capabilities.

1. Nutanix Disaster Recovery Guide v6.8, "Data Protection with Nearsync Replication", Section: "Nearsync Requirements and Limitations". This section explicitly states, "The source cluster must have at least three nodes."

2. Nutanix University, "Nutanix Data Protection and Disaster Recovery (DPDR) 6.5", Module: "Asynchronous, Nearsync, and Synchronous Replication". The courseware lists the prerequisites for Nearsync, including the three-node minimum for the source cluster.