Product : Nutanix, ECP [HCI]/5.19, Ultimate
Feature : Remote Replication Frequency, Disaster Recovery, Data Availability
Content Owner:  Herman Rutten
Summary
Synchronous to remote cluster: continuous
NearSync to remote clusters: 20 seconds*
Async to remote clusters: 1 hour
AWS/Azure Cloud: 1 hour
Xi Cloud: 1 hour
Details
AOS 5.5 introduced NearSync replication that leverages light-weight snapshots (LWS). The NearSync feature provides the ability to protect data with up to 1 minute RPO, minimizing data loss in case of a disaster. NearSync allows for a short time to recover, thus providing a low RTO. NearSync places no restrictions on latency or distance and works with all supported hypervisors. NearSync is a best-effort mechanism: whenever for example the network can’t sustain the low RPO, replication will temporarily transition out of near-sync. NearSync requires all changes to be handled in SSD, so a percentage of SSD space is reserved to be used by NearSync when it’s enabled.

In AOS 5.9+ Asynchronous and NearSync schedules can coexist in a protection domain.

AOS 5.17 enhanced NearSync RPO from 1 minute to 20 seconds. AOS 5.17 also introduced support for NearSync Replication (1-15 minutes RPO) with Xi Leap. Protection Policies can now be configured to use a NearSync replication schedule between two on-prem AHV/ESXi clusters or an on-prem AHV cluster and Xi Cloud Services.

AOS 5.17 introduced Synchronous replication (0 RPO) between two on-prem AHV clusters when using Xi Leap, Nutanix own built-in disaster recovery service offering. This includes replication of VM data, metadata, and associated policies. This means all VM attributes and associated security and orchestration policies are preserved in case of a failover. At this time only an unplanned failover can be performed when leveraging Synchronous replication between two on-prem AHV clusters when using Xi Leap. Before AOS 5.17 AHV did not provide any support for Synchronous replication.

NearSync and Continuous (Metro Availability) remote replication are only available in the Ultimate edition.

Nutanix Files supports asynchronous replication with a minimum interval of 1 hour. Nutanix Files 3.6 introduced support for NearSync.
Nutanix Files 3.6.1 introduces Async disaster recovery (DR) with a 1-hour RPO on physical nodes up 80TB.