3.5.1 Matrix Server Administration Guide

Chapter 14: Configure Device Monitors 239

enablement of the servers when determining where to activate a device

monitor.

Device Monitor Activeness Policy

ClusterPulse uses the following device monitor activeness policy to

determine the server or servers where it will make a device monitor

active. The policy described here is accurate for this release but it may

change in future releases or be modified by other PolyServe products.

The device monitor activeness policy decision is made as follows:

1. If the device monitor on a specific server is disabled, then the device

monitor will not be made active on that server.

2. ClusterPulse considers the list of servers that are both up and enabled

and that are configured for the device monitor. Note the following:

• A server that has not finished joining the matrix (see “Server

Access to the SAN” on page 283) is not considered up for the

purpose of activating the device monitor.

• A server is considered down if it loses coordinated communication

with the matrix (for example, the server crashed or was shut down,

Matrix Server was shut down on the server, the server failed to

schedule a matrix group communication process for an extended

period of time).

3. If the device monitor is multi-active, it will be active on all servers

passing evaluation for steps 1 and 2. If the device monitor is single-

active, then the list of servers is filtered by the following policy items

to determine the one server where the device monitor will be active.

4. From the list of servers that pass evaluation for steps 1 and 2,

ClusterPulse tries to find a server with all services up and enabled on

the virtual hosts associated with this device monitor. If ClusterPulse

finds a server meeting these conditions, it will use it, preferring

servers earlier in the list of servers for this device monitor.