Advantages And New Features Of The Ibm Power 775 - IBM Power Systems 775 Manual

Octants, SuperNode, and other components are described in the other sections of this book.
Node types
The following node types have other partial functions available for the cluster. In the
context of the 9125-F2C drawer, a node is an OSI image that is booted in an LPAR. There
are three general designations for node types on the 9125-F2C. Often these functions are
dedicated to a node, but a node can have multiple roles:
– Compute nodes
Compute nodes run parallel jobs and perform the computational functions. These
nodes are diskless and booted across the HFI network from a Service Node. Most of
the nodes are compute nodes.
– IO nodes
These nodes are attached to either the Disk Enclosure in the physical cluster or
external storage. These nodes serve the file system to the rest of the cluster.
– Utility Nodes
A Utility node offers services to the cluster. These nodes often feature more resources,
such as an external Ethernet, external, or internal storage. The following Utility nodes
are required:
• Service nodes: Runs xCAT to serve the operating system to local diskless nodes
• Login nodes: Provides a centralized login to the cluster
– Optional utility node:
• Tape subsystem server
Important: xCAT stores all system definitions as node objects, including the required EMS
console and the HMC console. However, the consoles are external to the 9125-F2C cluster
and are not referred to as cluster nodes. The HMC and EMS consoles are physically
running on specific, dedicated servers. The HMC runs on a System x® based machine
(7042 or 7310) and the EMS runs on a POWER 750 Server. For more information, see
1.7.1, "Hardware Management Console" on page 53 and 1.7.2, "Executive Management
Server" on page 53.
For more information, see this website:
http://publib.boulder.ibm.com/infocenter/powersys/v3r1m5/topic/p7had/p7had_775x
.pdf

1.3 Advantages and new features of the IBM Power 775

The IBM Power Systems 775 (9125-F2C) has several new features that make this system
even more reliable, available, and serviceable.
Fully redundant power, cooling and management, dynamic processor de-allocation and
memory chip & lane sparing, and concurrent maintenance are the main reliability, availability,
and serviceability (RAS) features.
The system is water-cooled, which gives a 100% heat capture. Some components are cooled
by small fans, but the Rear Door Heat exchanger captures this heat.
Chapter 1. Understanding the IBM Power Systems 775 Cluster
3