Administrator Guide

Virtual Volume
Director 1-1-A Director 1-1-B
VPLX-000376
Engine 1
Figure 12. Path redundancy: different ports
Combine multi-pathing software plus redundant volume presentation for continuous data availability in the presence of port
failures.
Back-end ports, local COM ports, and WAN COM ports provide similar redundancy for additional resilience.
Each director can service I/O for any other director in the cluster due to the redundant nature of the global directory and cache
coherency.
If one director in the engine fails, another director continues to service I/O from the host.
In the following figure, Director 1-1-A has failed, but Director 1-1-B services the host I/O that was previously being serviced by
Director 1-1-A.
Integrity and resiliency
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