Supported IBM Spectrum Virtualize 3-Site Orchestrator configurations

You can configure IBM Spectrum Virtualize 3-Site Orchestrator to manage replications in both remote-copy configurations and in HyperSwap configurations. Both configurations define sites and links between each site.

Each site can operate as either the Primary, Master, Auxiliary Near (Aux-Near), or Auxiliary Far (Aux-Far). These sites are defined slightly differently depending on whether you are configuring 3-site replication with Metro Mirror configurations or configuring HyperSwap® system with disaster recovery at a third site. The Comparison of site definitions provides an overview of these differences.

Site	Metro Mirror configuration	HyperSwap configuration
Primary	The primary site is the site from which data is replicated to two alternative sites. In a Metro Mirror configuration, the primary site can be changed based on outage. Usually the master site is the primary site; however, if the master site experiences an outage, administrators can switch application I/O and replication can shift to other systems on alternative sites.	With HyperSwap configurations, the primary site is automatically set since both sites in a HyperSwap configuration receive application I/O. The primary site receives I/O for a particular consistency group.
Master	The master site is added to the configuration first and the identifies automatically as the master site. The system at that site that is selected during configuration and is identified by unique management IP addresses.	The master site is one of the near sites in the HyperSwap system. In a HyperSwap system, I/O groups are configured at separated locations. The 3-Site Orchestrator always identifies the master site as site ID 1, but master and auxiliary near sites use the same management IP addresses and system name.
Auxiliary-Near	One of the near sites in 3-site configuration. This system is selected during configuration and has unique management IP addresses. The distance between the master site and the auxiliary-near site must not exceed 300 km.	For HyperSwap configurations, the auxiliary-near site is one of the near sites in the HyperSwap system. The always identifies the auxiliary-near site as Site ID 2, but master and auxiliary near sites use the same management IP addresses and system name. The distance between the master site and the auxiliary-near site must not exceed 300 km.
Auxiliary-Far	The system at the auxiliary-far site is the target for the asynchronous copy of the data from either the master site or the auxiliary-near site. The auxiliary-far site is typically 100s of km or more from the near sites.	The system at auxiliary-far site is the target for the asynchronous copy of the data on the HyperSwap system at near sites. The auxiliary-far site is typically 100s of km or more from the near sites.
Quorum site	NA	Quorum management is used in HyperSwap configurations. You either specify a site for quorum disk management or use an IP quorum application to manage a quorum disk that is used in tie-break situations.
Near sites	This term is used to describe the master and auxiliary sites.	This term describes the master and auxiliary sites refers to the sites on which the HyperSwap system is configured.

In addition, the master and auxiliary-near sites are connected to the auxiliary-far site through an active link and a standby link.

Active Link: The link to the auxiliary-far site from the master site or auxiliary-near site that is responsible for asynchronous replication of the data between the sites (periodic replication).
Standby Link: The link is in an idle copy state. The link is available when an active link fails.

Topologies for IBM Spectrum Virtualize 3-Site Orchestrator with Metro Mirror configurations

Topologies define how data is replicated and managed by IBM Spectrum Virtualize 3-Site Orchestrator. For remote copy configurations, the sites can be configured into either a Cascade or Star topology.

Cascade Topology: When a cascade topology is configured, the primary site replicates data to the partner-near site which in turn replicates data to the auxiliary-far site.
The cascade topology distributes the workload evenly between a production system and local-replication system.Figure 1 illustrates the cascade topology.
Figure 1. Cascade topology
Star Topology: When a star topology is configured, the primary site replicates data to both the partner-near site (auxiliary-near site in this example) and auxiliary-far site.
Figure 2 illustrates the star topology.
Figure 2. Star Topology

Topologies for IBM Spectrum Virtualize 3-Site Orchestrator with HyperSwap configurations

For HyperSwap configurations with IBM Spectrum Virtualize 3-Site Orchestrator, the following topologies are supported:

Figure 3 shows a 3-Site Orchestrator topology in which the primary site replicates data to the partner-near site, which in turn replicates data to the auxiliary-far site. The active links are shown as green lines and the standby link is shown as a yellow line.

Figure shows topology — Figure 3. Primary site replicates data to the auxiliary-near site

Figure 4 shows a IBM Spectrum Virtualize 3-Site Orchestrator topology in which the primary site replicates data to both the partner-near site and the auxiliary-far site. The active links are shown as green lines and the standby link is shown as a yellow line.