3.5.1 Matrix Server Administration Guide

Chapter 14: Configure Device Monitors 237

(“Associated” service and device monitors are those monitors that are

associated with the same virtual host as this device monitor.)

• Single-Always-Active. The monitor is active on only one of the

selected servers. Upon server failure, the monitor will fail over to an

active server even if all associated service and device monitors are

down. (“Associated” service and device monitors are those monitors

that are associated with the same virtual host as this device monitor.)

• Multi-Active. The monitor is active simultaneously on all servers

configured for the monitor.

By default, DISK and SHARED_FILESYSTEM monitors are multi-active. This

configuration allows the device monitor to probe a shared resource such

as a network gateway or a SAN partition containing a PSFS filesystem.

CUSTOM monitors can be either single-active or multi-active, depending

on the service or device being monitored.

SHARED_FILESYSTEM Device Monitor

If you have created a virtual host for applications that obtain their data

from a

PSFS filesystem, or if you just want to monitor access to a PSFS

filesystem, you can use the

SHARED_FILESYSTEM device monitor to

ensure that the filesystem is healthy and the virtual host remains

available.

SHARED_FILESYSTEM device monitor is associated with a specific

PSFS filesystem. The monitor probes the filesystem at periodic intervals to

determine the filesystem health. The probe attempts to open and read a

file located on the filesystem. When you configure the monitor, you can

specify the file to be read, or you can let Matrix Server create a file for this

purpose.

SHARED_FILESYSTEM device monitor attempts to be active on each

server specified in its configuration. The device monitor probe reports an

UP status for the filesystem only if it is mounted and file content can be

read from the filesystem.