What is the maximum distance between a standard clustered pair?

In a standard NetApp ONTAP High-Availability (HA) pair configuration, the two controller nodes must be located within the same data center. The maximum supported distance between these two nodes is 500 meters. This distance allows for physical separation for fault tolerance, such as placement in different fire-containment zones within a single building. This configuration relies on high-speed, low-latency cluster interconnect links, typically using fiber optic cabling and appropriate transceivers to span the distance while maintaining performance for state mirroring and failover operations. Configurations exceeding this distance require a MetroCluster solution.

A. 10 meters: This is a common length for direct-attach copper (DAC) cables but is far below the maximum supported distance for a standard HA pair.

B. 50 meters: While a valid distance achievable with fiber optics, this is not the maximum limit for a standard HA configuration.

C. 100 meters: This is a typical distance limit for Ethernet over copper cabling but does not represent the maximum for fiber-based cluster interconnects.

1. NetApp ONTAP 9 Documentation Center

High-Availability Management

"High-availability configuration overview": "In a standard HA pair configuration

the nodes must be located in the same rack or in the same data center

with a maximum distance of 500 meters between them." (This statement is consistently found across multiple ONTAP 9.x versions).

2. NetApp TR-4684

"Best Practices for MetroCluster Design and Implementation": This technical report differentiates standard HA from MetroCluster

implicitly defining the former's scope. Section 2.1

"MetroCluster Architectures

" describes standard HA as a local solution

contrasting it with the long-distance capabilities of MetroCluster

thereby reinforcing the 500m limit as the boundary for "standard" configurations.

3. NetApp Hardware Universe (hwu.netapp.com): When configuring cluster interconnect switches and cables

the supported cable types and lengths are specified. For example

using 100GbE SR4 optics allows for distances on OM4 multimode fiber that support the 500m separation for standard HA pairs. The combination of supported switches

cables

and optics validates this maximum distance.