User's Guide

Overview

HyperFabric Concepts

Chapter 1

HyperFabric Concepts

Some basic HyperFabric concepts and terms are brieﬂy described below.

The fabric is the physical conﬁguration that consists of all of the HyperFabric adapters,

the HyperFabric switches (if any are used) and the HyperFabric cables connecting them.

The network software controls data transfer over the fabric.

A HyperFabric conﬁguration contains two or more HP 9000 systems and optional

HyperFabric switches. Each HP 9000 acts as a node in the conﬁguration. Each node has

a minimum of one and a maximum of eight HyperFabric adapters installed in it. (See

Chapter 2, “Planning the Fabric,” on page 19for information about the maximum

number of adapters that can be installed in each system). HyperFabric supports a

maximum of 4 HyperFabric switches. HyperFabric switches can be meshed, and

conﬁgurations with up to four levels of meshed switches are supported.

A HyperFabric cluster can be planned as a High Availability (HA) conﬁguration, when

it is necessary to ensure that each node can always participate in the fabric. This is done

by using MC/ServiceGuard, MC/LockManager, and the Event Monitoring Service (EMS).

Conﬁgurations of up to eight nodes are supported under MC/ServiceGuard.

Relocatable IP addresses can be used as part of an HA conﬁguration. Relocatable IP

addresses permit a client application to reroute through an adapter on a remote node,

allowing that application to continue processing without interruption. The rerouting is

transparent. This function is associated with MC/ServiceGuard (see “Conﬁguring

ServiceGuard for HyperFabric Relocatable IP Addresses” on page 81). When the monitor

for HyperFabric detects a failure and the backup adapter takes over, the relocatable IP

address is transparently migrated to the backup adapter. Throughout this migration

process, the client application continues to execute normally.

When you start HyperFabric (with the clic_start command, through SMH or by

booting the HP 9000 system), you start the management process. This process must

be active for HyperFabric to run. If the HyperFabric management process on a node

stops running for some reason (for example, if it is killed), all HyperFabric-related

communications on that node are stopped immediately. This makes the node

unreachable by other components in the fabric.

When you start HyperFabric, the fabric is, in effect, veriﬁed automatically. This is

because each node performs a self diagnosis and veriﬁcation over each adapter installed

in the node. Also, the management process performs automatic routing and conﬁguring

for each switch (if switches are part of the fabric). You can, if needed, run the clic_stat

command to get a textual map of the fabric, which can be used as another quick

veriﬁcation.

Notice that the commands you use to administer HyperFabric all have a preﬁx of clic_ ,

and some of the other components have CLIC as part of their name (for example, the

CLIC ﬁrmware and the CLIC software). CLIC stands for CLuster InterConnect, and it is

used to differentiate those HyperFabric commands/components from other

commands/components. For example, the HyperFabric command clic_init is different

from the HP-UX init command.