Nutanix NCP-BC-7.5 - Nutanix Certified Professional - Business Continuity (NCP-BC) 7.5

Nutanix NearSync replication provides low RPOs (1 to 15 minutes) by using " Lightweight Snapshots " (LWS). NearSync has higher performance and hardware requirements than standard Asynchronous replication because it must handle metadata operations and data transfers much more frequently.

For a cluster to support NearSync, it must have sufficient high-performance storage to handle the additional I/O load associated with LWS. On hybrid nodes (those with both SSDs and HDDs), Nutanix has a specific hardware requirement: each node must have at least two SSDs. This is because the NearSync LWS metadata and incoming replicated data are initially written to the SSD tier to ensure low latency and high throughput. A single SSD per node is typically insufficient to handle both active VM production I/O and the high-frequency NearSync overhead without performance degradation. Therefore, adding a second SSD to each node (Option D) is the mandatory modification. While upgrading to NVMe (Option A) or adding more nodes (Option B) would also improve performance, adding a second SSD is the minimum " cost-effective " requirement specified by Nutanix engineering for NearSync support on hybrid clusters. Meeting these hardware prerequisites is essential to ensure that the cluster can maintain the 15-minute RPO without transitioning back to an hourly schedule due to resource constraints.

In modern Nutanix Disaster Recovery (using Prism Central-based Protection Policies), storage placement is often governed by Storage Policies rather than simple container-to-container mapping. Storage Policies use Nutanix Categories to determine where a VM should be placed to meet performance or compliance requirements. In this scenario, the VMs were successfully replicated and recovered, but they were placed in " all the storage containers " rather than the intended FIN-PROD container at the Marseille site. This indicates that while the data arrived, the " destination placement rules " were missing. If a storage policy was created on the Paris cluster to keep these VMs in FIN-PROD but that policy was not mirrored or assigned at the Marseille cluster, the system defaults to the Acropolis Dynamic Scheduler (ADS) placement. ADS will distribute the VMs across all available containers to balance load and capacity, leading to the " scattered " result observed. To resolve this and ensure consistent failover behavior, the administrator must ensure that both the categories and the corresponding storage policies are identical and active at both availability zones. While a missing container (Option C) would typically cause a replication failure rather than scattered recovery, a missing storage policy specifically explains the lack of orchestrated placement during the failover event.