Managing Serviceguard NFS for Linux, March 2009

Figure 1-3 A Host Configured as Adoptive Node for Multiple Packages
Alternatively, you can prevent Node_B from adopting more than one package at a time by setting
a package control function in the package control script. With the package control function set,
Node_B may adopt the package of the first node that fails, but if the second node fails, Node_B
will not adopt its package. The package control function prevents a node from becoming
overloaded by adopting too many packages. If an adoptive node becomes overloaded, it can fail.
For more information, refer to the "Package Control Script for pkg01" (page 51) and “Package
Control Script for pkg02” (page 53) sections."
Cascading Failover with Multiple Adoptive Nodes
Consider a package that is configured up to three adoptive nodes. Figure 1-4 shows this
configuration. If Node_A fails, Pkg_1 is adopted by Node_B. However, if Node_B is down,
Pkg_1 is adopted by Node_C, and if Node_C is down, Pkg_1 is adopted by Node_D. The adoptive
nodes are listed in the package configuration file, which was generated by using cmmakepkg
-p file command (see Managing HP Serviceguard for Linux, Chapter 6) in the order in which
they will be tried. Note that all four nodes must have access to the disks for the Pkg_1 file systems.
12 Serviceguard NFS for LINUX Introduction