3.5.1 Matrix Server Administration Guide

Chapter 1: Introduction 11

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 designed

either to watch a part of a server such as a local disk drive or to monitor a

PSFS filesystem. A device monitor is assigned to one or more servers.

Matrix Server provides several built-in device monitors. You can also

define your own custom device monitors.

When a device monitor is assigned to a server, 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 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 1 GB server and an 8 GB

server, with a ratio of 8), paging can increase on the smallest server to the

extent that overall matrix performance is significantly reduced.