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SplitSite Configurations

A SplitSite configuration connects two physical machines in two separate sites. It is a disaster-tolerant deployment that maintains hardware redundancy as well as redundancy of physical computer rooms and the buildings containing them. Because of the geographic separation, a SplitSite configuration requires careful planning of component placement and more complex networking topologies. For SplitSite configurations, Stratus strongly recommends that you use the quorum service because a SplitSite configuration exposes the A-Link networks to other potential failure scenarios.

SplitSite Network Requirements lists the requirements for networks in a SplitSite configuration.

SplitSite and Quorum Service

In a SplitSite configuration, configure two quorum-service computers in compliance with the best practices recommended for quorum deployment (see Quorum Servers Considerations). In any SplitSite configuration, a preferred quorum-service computer is located in a third facility, and an alternate is located in a fourth site (or carefully placed in the third). The networks are interconnected.

Quorum-service computers should be as isolated as possible. If both must be placed in a common (third) site, make sure that they do not depend on common power sources.

Physical connectivity between an everRun PM and the quorum-service computers must not route through the other PM's site.

Placing a quorum-service computer in the same site as one of the everRun PMs ensures data integrity. However, some site failures may then require that the VMs be shut down until manually recovered.

The management network physically connects the everRun PMs and the quorum-service computers. For this to work properly, you must configure each everRun PM to use a different gateway to reach the quorum-service computers. If the two PMs use the same gateway to reach the quorum-service computers, data integrity is ensured during failures. However, some site failures may then require that the VMs be shut down until manually recovered.

Related Topics

Quorum Servers

Network Architecture Overview

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