Hmc X; Data Flow - IBM Power Systems 775 Manual

The service network is a private, out-of-band network that is dedicated to managing the
Power 775 clusters hardware. This network provides Ethernet based connectivity between
the FSP of the CEC, the frame control BPA, the EMS, and the associated HMCs. Two
identical network switches (ENET A and ENET B in the figure) are deployed to ensure high
availability of these networks.
The management network is primarily responsible for booting all nodes, the designated
service nodes, compute nodes, and I/O nodes, and monitoring their OS image loads. This
management network connects the dual EMSs running the system management software
with the various Power 775 servers of the cluster. Both the service and management
networks must be considered private and not routed into the public network of the enterprise
for security reasons.
10Gb
Connections are 1Gb

HMC x

10Gb
eNet Unless Shown
explicitly
Red = EMS
10Gb
Black = HMC
10Gb
HMC 2
HMC 1
EMS 1
EMS 2
10Gb
10Gb
10Gb
10Gb
.
Figure 1-46 Logical structure of service and management networks

1.7.5 Data flow

This section provides a high-level description of the data flow on the cluster service network
and cluster management operations.
After discovery of the hardware components, their definitions are stored in the xCAT database
on the EMS. HMCs, CECs, and frames are discovered via Service Location Protocol (SLP) by
xCAT. The discovery information includes model and serial numbers, IP addresses, and so
on. The Ethernet switch of the service LAN also is queried to determine which switch port is
connected to each component. This discovery is run again when the system is up, if wanted.
The HFI/ISR cabling also is tested by the CNM daemon on the EMS. The disk enclosures and
their disks are discovered by GPFS services on these dedicated nodes when they are booted
up.
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IBM Power Systems 775 for AIX and Linux HPC Solution
ENET A
Management
Network
Service
Network
Frame - 1
BPCH-A
HUB A
BPCH-B
HUB B
ENET B
Service
Network
Management
Network
Frame - 2
BPC-A BPC-A
BPA-A
BPC-A BPC-A
BPC-B BPC-B
BPA-B
BPC-B BPC-B
DCCA-A DCCA-A
DCCA-A DCCA-A
DE (U29)
DCCA-B DCCA-B
DCCA-B DCCA-B
BPCH-A
DCCA-A DCCA-A
DCCA-A DCCA-A
HUB A
CEC (U27)
DCCA-B DCCA-B
DCCA-B DCCA-B
DCCA-A DCCA-A
DCCA-A DCCA-A
CEC (U25)
DCCA-B DCCA-B
DCCA-B DCCA-B
DCCA-A DCCA-A
PCI
DCCA-A CEC (U23) DCCA-A
17
(Utility)
DCCA-B DCCA-B
DCCA-B DCCA-B
DCCA-A DCCA-A
DCCA-A DCCA-A
CEC (U21)
DCCA-B DCCA-B
DCCA-B DCCA-B
DCCA-A DCCA-A
DCCA-A DCCA-A
CEC (U19)
DCCA-B DCCA-B
DCCA-B DCCA-B
DCCA-A DCCA-A
DCCA-A DCCA-A
CEC (U17)
DCCA-A DCCA-A
DCCA-B DCCA-B
DCCA-A DCCA-A
DCCA-A DCCA-A
CEC (U15)
DCCA-B DCCA-B
DCCA-B DCCA-B
DCCA-A DCCA-A
DCCA-A DCCA-A
CEC (U13)
DCCA-B DCCA-B
DCCA-B DCCA-B
DCCA-A DCCA-A
DCCA-A BPCH-B DCCA-A
CEC (U11)
HUB B
DCCA-B DCCA-B
DCCA-B DCCA-B
DCCA-A DCCA-A
DCCA-A DCCA-A
CEC (U9)
DCCA-B DCCA-B
DCCA-B DCCA-B
DCCA-A DCCA-A
DCCA-A DCCA-A
CEC (U7)
DCCA-B DCCA-B
DCCA-B DCCA-B
DCCA-A DCCA-A
DCCA-A DCCA-A
CEC (U5)
DCCA-B DCCA-B
DCCA-B DCCA-B
Frame - 3
BPC-A
BPA-A
BPC-A
BPC-B
BPA-B
BPC-B
DCCA-A
DCCA-A
DE (U29) DE (U29)
DCCA-B
DCCA-B
BPCH-A
DCCA-A
DCCA-A
HUB A
CEC (U27) CEC (U27)
DCCA-B
DCCA-B
DCCA-A
DCCA-A
CEC (U25) CEC (U25)
DCCA-B
DCCA-B
DCCA-A
DCCA-A CEC (U23)
CEC (U23)
(Utility)
DCCA-B
DCCA-B
DCCA-A
DCCA-A
CEC (U21) CEC (U21)
DCCA-B
DCCA-B
DCCA-A
DCCA-A
CEC (U19) CEC (U19)
DCCA-B
DCCA-B
DCCA-A
DCCA-A
CEC (U17) CEC (U17)
DCCA-A
DCCA-B
DCCA-A
DCCA-A
CEC (U15) CEC (U15)
DCCA-B
DCCA-B
DCCA-A
DCCA-A
CEC (U13) CEC (U13)
DCCA-B
DCCA-B
DCCA-A
BPCH-B DCCA-A
CEC (U11) CEC (U11)
HUB B
DCCA-B
DCCA-B
DCCA-A
DCCA-A
CEC (U9) CEC (U9)
DCCA-B
DCCA-B
DCCA-A
DCCA-A
CEC (U7) CEC (U7)
DCCA-B
DCCA-B
DCCA-A
DCCA-A
CEC (U5) CEC (U5)
DCCA-B
DCCA-B
.
BPA-A
BPA-B
PCI
17
.