3.4.0 Matrix Server Administration Guide

Chapter 1: Introduction 8

Matrix Server includes several built-in service monitors for monitoring

well-known network services. You can also configure custom monitors

for other services.

A device monitor is similar to a service monitor; however, it is assigned to

one or more servers. Matrix Server provides several built-in device

monitors. The

DISK device monitor can be used to watch local disk drives

or to check access to a partition on a SAN disk. The

GATEWAY device

monitor watches gateway devices. You can also define your own custom

device monitors.

By default, when a device monitor is assigned to a server, all virtual hosts

on that server are dependent on the device monitor. However, you can

select the virtual hosts that will be dependent on the device monitor. If a

device monitor indicates that a device is not functioning properly on the

primary server, Matrix Server transfers the dependent virtual host

addresses from the primary server to a backup server.

Event Notification

A notifier defines how the matrix handles state transition, error, warning,

and informational messages. You can configure a notifier with a

combination of events and originating matrix entities and then supply a

script that specifies the action the notifier should take. For example, you

could forward events to e-mail or to any other user-defined process.

Matrix Design Guidelines

Be sure to consider the following guidelines when planning the physical

configuration of your Matrix Server matrix.

Server Memory

Memory resources are consumed on each matrix server to manage the

state necessary to preserve the coherency of shared filesystems. For this

reason, the servers in the matrix should have approximately equal

amounts of physical memory. As a guideline, the ratio of memory

between the smallest and largest servers should not exceed 2. For

example, the smallest server could have 1 GB of memory and the largest

server 2 GB. If this ratio is exceeded (such as a 256 MB server and a 2 GB