HP-UX Virtual Partitions Administrator's Guide (includes A.05.02)

Introduction

HP Product Interaction

Chapter 1

HP Product Interaction

• Processor Terminology

Processing resources under vPars, both as input arguments and command outputs, are described as

“CPUs.” For multi-core processors such as the PA-8800 and dual-core Intel Itanium 2 processors, the term

“CPU” is synonymous with “core.” The term “processor” refers to the hardware component that plugs into

a processor socket. Therefore a single processor can have more than one core, and vPars commands will

refer to the separate cores as distinct “CPUs,” each with its own hardware path.

Two vPars terms pre-date multi-core processors, so they are exceptions to this terminology:

— “boot processor”, which refers to the CPU (that is, core) on which the OS kernel of the virtual partition

was booted, and

— “cell local processor (CLP),” which refers to a CPU on a speciﬁed cell.

For more information on dual-core processors, see “CPU: Dual-Core Processors” on page 225.

• Hyperthreading

Hyperthreading is a new feature supported in HP-UX 11i v3 (11.31) environments on servers with the

dual-core Intel Itanium 2 processors. It provides for executing multiple threads on a single processor core;

each thread is abstracted as a “logical CPU” (LCPU). In vPars A.05.01, you can enable and disable

hyperthreading with the vPars Monitor; however, in a mixed HP-UX 11i v2/v3 vPars environment, any

virtual partitions running vPars A.04.xx/11.23 will not boot unless hyperthreading is disabled. For more

information on hyperthreading, see “CPU: Hyperthreading ON/OFF (HT ON/OFF)” on page 228 and

“Setting Hyperthreading (HT ON/OFF) and cpuconﬁg Primer” on page 301.

CPUs are assigned to virtual partitions on a core basis, and not on a logical CPU (LCPU) basis.

• asyncdsk driver

Many applications, such as databases, use the asyncdsk driver to lock down memory for I/O transfers. As

of this writing, the asyncdsk driver does not support memory deletion. As a result, if the driver has

locked down any ﬂoat memory, then that portion of memory cannot be deleted from a virtual partition.

See the most recent version of the HP-UX Virtual Partitions Release Notes for more information.

• PCI On-Line Addition and Replacement (OL*)

Except for the functions stated below, OL* for PCI slots works the same on a vPars server as it does on a

non-vPars server. Note that you can execute PCI OL* functions only on the PCI slots that the virtual

partition owns.

PCI doorbells (the physical attention button on the system) are supported beginning with the HP-UX

December 2003 HWE release and vPars A.03.01.

(PA-RISC only) In a vPars system, a reboot of the virtual partition does not power on a slot that was

powered off prior to the reboot. If you wish to power on the slot, you need to do this manually after the

reboot using the rad command: rad -i

slot_id

For changes in the use of OL* on HP-UX 11i v2 (11.23), please see the 11.23 On-Line Addition and

Replacement documentation at http://docs.hp.com.

The PCI OL* error recovery features that are supported in 11.31 are also supported within a vPars

environment. For complete information on PCI OL* error recovery, see the following documents available

at http://docs.hp.com: