Hard Partitioning: Dynamic Domains - Oracle Solaris 10 System Virtualization Essentials - page 58

Figure 2.12 shows how memory is mirrored on the M8000 and M9000. This
approach is very different from that taken by the M4000/M5000. Memory
is mirrored across adjacent MACs on the same system board, which means
memory mirroring is possible only when the system board is configured in
Uni-XSB mode. While this will be the most common mode on these higher-
end systems, it does require a trade-off between memory availability and
domain granularity.

Figure 2.12 Memory Mirroring on M8000/M9000

Domain Configuration. The choices for different ways to create domains
are more pronounced on the M8000 and M9000. Improving availability can
be achieved in different ways. Consider a configuration of two domains using
just two CMU/IOU boards. The model shown at the top of Figure 2.13 shows
Domain 1 completely on XSB01 and Domain 2 completely on XSB02. In this
model, a failure on a system board affects only a single domain. Likewise,
repair will affect only a single domain. If the MAC has a complete failure,
it is possible that the domain would be down until repair. Now consider the
model shown at the bottom of Figure 2.13. Both domains have the same
amount of resources as before, but in a different configuration—namely, the

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