Nutanix NearSync replication uses Lightweight Snapshots (LWS) to achieve RPOs as low as 1 minute. To maintain this aggressive schedule, the system must be able to replicate all the " delta " changes (the data that has changed since the last snapshot) within the RPO window. If the data change rate (churn) of the VM increases, or if the available network bandwidth decreases, the system may find that it cannot complete the replication of one LWS before the next one is due.

When the Nutanix Cerebro service detects that it is consistently missing its NearSync target, it will automatically " downshift " the replication to a standard Asynchronous schedule (typically hourly) to ensure that the VM remains protected at a manageable frequency. This is a self-healing mechanism designed to prevent replication jobs from stacking up and causing cluster instability. Insufficient bandwidth (Option D) is the most common cause for this downshift, as the " Snapshot-on-wire " cannot be moved fast enough to satisfy the 5-minute requirement. While high RTT (Option A) is a requirement for Synchronous replication, NearSync is designed to handle higher latencies (up to 80ms or more), making bandwidth the primary bottleneck in these troubleshooting scenarios.