Smart DR in Nutanix Files, part of Nutanix Unified Storage (NUS), is a disaster recovery (DR) solution that simplifies the setup of replication policies between file servers (e.g., using NearSync, as seen in Question 24). After configuring a Smart DR policy, the administrator expects to see it in the Policies tab in Prism Central, but it is not visible despite confirmed connectivity between FSVMs and Prism Central via port 9440 (used for Prism communication, as noted in Question 21). This indicates a potential mismatch or configuration issue.

Analysis of Options:

Option A (The primary and recovery file servers do not have the same version): Correct. Smart DR requires that the primary and recovery file servers (source and target) run the same version of Nutanix Files to ensure compatibility. If the versions differ (e.g., primary on Files 4.0, recovery on Files 3.8), the Smart DR policy may fail to register properly in Prism Central, resulting in it not appearing in the Policies tab. This is a common issue in mixed-version environments, as Smart DR relies on consistent features and APIs across both file servers.

Option B (Port 7515 should be open for all External/Client IPs of FSVMs on the Source and Target cluster): Incorrect. Port 7515 is not a standard port for Nutanix Files or Smart DR communication. The External/Client network of FSVMs (used for SMB/NFS traffic) communicates with clients, not between FSVMs or with Prism Central for policy management. Smart DR communication between FSVMs and Prism Central uses port 9440 (already confirmed open), and replication traffic between FSVMs typically uses other ports (e.g., 2009, 2020), but not 7515.

Option C (The primary and recovery file servers do not have the same protocols): Incorrect. Nutanix Files shares can support multiple protocols (e.g., SMB, NFS), but Smart DR operates at the file server level, not the protocol level. The replication policy in Smart DR replicates share data regardless of the protocol, and a protocol mismatch would not prevent the policy from appearing in the Policies tab—it might affect client access, but not policy visibility.

Option D (Port 7515 should be open for all Internal/Storage IPs of FSVMs on the Source and Target cluster): Incorrect. Similar to option B, port 7515 is not relevant for Smart DR or Nutanix Files communication. The Internal/Storage network of FSVMs is used for communication with the Nutanix cluster’s storage pool, but Smart DR policy management and replication traffic do not rely on port 7515. The key ports for replication (e.g., 2009, 2020) are typically already open, and the issue here is policy visibility, not replication traffic.

Why Option A?

Smart DR requires compatibility between the primary and recovery file servers, including running the same version of Nutanix Files. A version mismatch can cause the Smart DR policy to fail registration in Prism Central, preventing it from appearing in the Policies tab. Since port 9440 connectivity is already confirmed, the most likely issue is a version mismatch, which is a common cause of such problems in Nutanix Files DR setups.

Exact Extract from Nutanix Documentation:

From the Nutanix Files Administration Guide (available on the Nutanix Portal):

“Smart DR requires that the primary and recovery file servers run the same version of Nutanix Files to ensure compatibility. A version mismatch between the source and target file servers can prevent the Smart DR policy from registering properly in Prism Central, resulting in the policy not appearing in the Policies tab.”