IBM Power 570 and IBM Power 595 (POWER6 ... - IBM Redbooks

adapter slot. A PCIe adapter cannot be installed in a PCI or PCI-X adapter slot, and a PCI
or PCI-X adapter cannot be installed in a PCIe slot.
► I/O adapter or I/O controller terminology
You will see the word adapter and the word controller as the title of various I/O feature
numbers, each of which supports attachment of other I/O hardware, such as tape or disk
devices or a communications (LAN or WAN) cable. In this case, the terms adapter and
controller mean the same general capability. In some System i I/O documentation, you
might also see the acronym IOA, meaning I/O adapter. In this paper, we generally use
IOA, controller, and adapter interchangeably.
Some hardware documentation refers to an adapter or controller as Host Bus Adapter
(HBA). This term is typically used in both IBM and non-IBM publications when referring to
adapters and controllers that use one of the following:
– A Small Computer System Interface (iSCSI) adapter that supports IBM i Windows®
integration with an IBM System x computer HBA
– A Fibre Channel adapter connection within an IBM external Storage Server, for
example, the DS8000 series of storage servers
► I/O processor (IOP) and IOA relationships
System i has a history of supporting a hardware component called an I/O Processor
(IOP). IOPs are used as a front end to older technology IOAs, providing support or
efficiencies that are not available in the older IOAs. Some IOPs can support multiple IOAs.
System p configurations have not used IOPs.
Originally, the IOP processor technology was faster than IOA processor technology. Earlier
IBM i operating system code implementation took advantage of off-load protocol coding
and decoding from the CPU. Thus, microcode was placed in the IOP to deliver the fastest
possible performance for customers. Some examples include SNA and TCP/IP support
where some low level communication data protocol processing was a joint venture
between an IOA and its supporting IOP. The operating system’s microcode understands
this IOP-IOA relationship.
IOAs introduced over the last two to three years have very fast processors and do not
require a supporting IOP. Among the System i community, these adapters are sometimes
referred to as smart IOAs that can operate with or without an IOP. Sometimes these IOAs
are also referred to as a dual mode IOA.
IOAs also do not run with an IOP, which is sometimes referred to as an IOP-less IOA.
AIX or Linux client partitions hosted by an IBM i partition are not aware of any unique IBM i
I/O hardware requirements.
AIX or Linux users consider IOP-less IOAs as the “normal” I/O environment. New orders
for IBM i, AIX, and Linux operating systems should specify the smart or IOP-less IOAs.
However, some tape devices supported under IBM i require an IOA that requires an IOP.
Other chapters in this publication, such as Chapter 4, “Feature descriptions and related
information” on page 187 and Chapter 10, “Tape and optical storage attachment
summary” on page 825, contain this information.
The POWER6 Power 520, Power 550, and Power 570 processor enclosure does not
support IOP cards. Thus, if an IOP-IOA combination is required for functional support
reasons, a “remote” RIO-2 I/O loop and an appropriate I/O enclosure supporting an IOP is
required. The one processor configurations of the Power 520 8203-E4A and 9407-M15 do
not support remote I/O loops. See 1.2.4, “I/O enclosures attaching using 12x or RIO-2 I/O
loop adapters” on page 13 for more information about I/O enclosures.
Chapter 1. Introduction to the POWER6 IBM Power System servers 11