Managing HP Serviceguard for Linux Ninth Edition, April 2009

Before the Control Script Starts
First, a node is selected. This node must be in the package’s node list, it must conform
to the package’s failover policy, and any resources required by the package must be
available on the chosen node. One resource is the subnet that is monitored for the
package. If the subnet is not available, the package cannot start on this node. Another
type of resource is a dependency on another package. If monitoring shows a value for
a configured resource that is outside the permitted range, the package cannot start.
Once a node is selected, a check is then done to make sure the node allows the package
to start on it. Then services are started up for a package by the control script on the
selected node. Strictly speaking, the run script on the selected node is used to start a
legacy package; the master control script starts a modular package.
During Run Script Execution
Once the package manager has determined that the package can start on a particular
node, it launches the script that starts the package (that is, a package’s control script
or master control script is executed with the start parameter). This script carries out the
following steps:
1. Executes any external_pre_scripts (modular packages only; see “About External
Scripts” (page 137))
2. Activates volume groups or disk groups.
3. Mounts file systems.
4. Assigns package IP addresses to the LAN card on the node (failover packages
only).
5. Executes any customer-defined run commands (legacy packages only; see “Adding
Customer Defined Functions to the Package Control Script ” (page 257)) or
external_scripts (modular packages only; see “About External Scripts” (page 137)).
6. Starts each package service.
7. Exits with an exit code of zero (0).
64 Understanding Serviceguard Software Components