Utility Nodes - IBM Power Systems 775 Manual

1.7.7 Utility nodes

This section defines the utility node for all Power 775 frame configurations.
A CEC is defined as a Utility CEC (node) when it has the Management server (Service node)
as an LPAR. Each frame configuration is addressed individually. A single Utility LPAR
supports a maximum of 1536 LPARs, one of which is an LPAR (one Utility LPAR and 1535
other LPARs). Recall that a node contains four POWER7 chips and a single POWER7
contains a maximum of one LPAR; therefore, a CEC contains 8 x 4 = 32 POWER7 chips. This
configuration results in up to 32 LPARs per CEC.
This result of 1536 LPARs translates to the following figures:
1536 POWER7 chips
384 Octants (1536 / 4 = 384)
48 CECs (a CEC can contain up to 32 LPARS; therefore, 1536 / 32 = 48)
There are always redundant utility nodes that reside in different frames when possible. If there
is only one frame and multiple SuperNodes, the utility node resides in different SuperNodes. If
there is only one SuperNode, the two utility nodes reside in different CECs. If there is only one
CEC, the two utility LPARs reside in different Octants in the CEC.
The following defined utility CEC is used in the four-frame, three-frame, two-frame, and
single-frame with 4, 8, and 12 CEC configurations. The single frame with 1 - 3 CECs uses a
different utility CEC definition. These utilities CEC definitions are defined in their respective
frame definition sections.
The utility LPAR resides in Octant 0. The LPAR is assigned only to a single POWER7.
Figure 1-47 on page 59 shows the eight Octant CEC and the location of the Management
LPAR. The two Octant and the four Octant CEC might be used as a utility CEC and follows
the same rules as the eight Octant CEC.
58
IBM Power Systems 775 for AIX and Linux HPC Solution