Managing HP Serviceguard for Linux Ninth Edition, April 2009

Planning for Expansion

Bear in mind that a cluster with more than 4 nodes cannot use a lock LUN. So if you

plan to add enough nodes to bring the total to more than 4, you should use a quorum

server.

Using a Quorum Server

The Quorum Server is described under “Use of the Quorum Server as a Cluster Lock”

(page 46). See also “Cluster Lock” (page 45).

A quorum server:

• Can be used with up to 150 clusters, not exceeding 300 nodes total.

• Can support a cluster with any supported number of nodes.

• Can communicate with the cluster on up to two subnets (a primary and an

alternate).

IMPORTANT: If you plan to use a Quorum Server, make sure you read the HP

Serviceguard Quorum Server Version A.04.00 Release Notes before you proceed. You can

find them at: http://www.docs.hp.com -> High Availability -> Quorum

Server. You should also consult the Quorum Server white papers at the same location.

Quorum Server Worksheet

You can use the Quorum Server Worksheet (page 312) to identify a quorum server for

use with one or more clusters. You may want to record the following:

Quorum Server Host

The host name for the quorum server.

IP Address

The IP address(es) by which the quorum server will

communicate with the cluster nodes.

Supported Node Names

The name (39 characters or fewer) of each cluster node

that will be supported by this quorum server. These

entries will be entered into qs_authfile on the

system that is running the quorum server process.

Volume Manager Planning

When designing your disk layout using LVM, you should consider the following:

• The volume groups that contain high availability applications, services, or data

must be on a bus or buses available to the primary node and all adoptive nodes.

• High availability applications, services, and data should be placed in volume

groups that are separate from non-high availability applications, services, and

data.

Volume Manager Planning 99