ServerNet Cluster Manual

ServerNet Cluster Description
ServerNet Cluster Manual—520575-003
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X and Y Fabrics
External ServerNet Fabrics
An external ServerNet X or Y fabric delivers ServerNet packets between servers that
are nodes in a ServerNet cluster. See Figure 1-2 on page 1-4 and Figure 1-3 on
page 1-6.
External fabrics provide intersystem communication. The external ServerNet fabrics
are an extension of the internal ServerNet fabrics beyond the single-system boundary.
Every ServerNet cluster has identical, external X and Y fabrics. Messages are routed
to the external fabrics using a special plug-in card (PIC) installed in the MSEBs in slots
51 and 52 of group 01 of each node.
The external system area network manager processes (SANMANs) in each node of a
ServerNet cluster manage the external ServerNet fabrics. Every SANMAN process has
equal rights to manage the external fabrics.
Figure 1-8. Simplified Logical Diagram Showing Internal X and Y Fabrics
vst909.vsd
Disks
Y fabric
Processor
XY
Processor
XY
ServerNet Link (X fabric)
ServerNet Link (Y fabric)
(Used for clarity when both fabrics are shown)
X
fabric
Y
fabric
ServerNet
Adapter
ServerNet
Adapter
ServerNet
Adapter
ServerNet
Adapter
X fabric