Managing Serviceguard 12th Edition, March 2006

Understanding Serviceguard Software Components
How the Package Manager Works
Chapter 376
A package switch involves moving failover packages and their associated
IP addresses to a new system. The new system must already have the
same subnet configured and working properly, otherwise the packages
will not be started.
With package failovers, TCP connections are lost. TCP applications must
reconnect to regain connectivity; this is not handled automatically. Note
that if the package is dependent on multiple subnets, all of them must be
available on the target node before the package will be started.
If the package has a dependency, the dependency must be met on the
target node before the package can start.
The switching of relocatable IP addresses is shown in Figure 3-5 and
Figure 3-6. Figure 3-5 shows a two node cluster in its original state with
Package 1 running on Node 1 and Package 2 running on Node 2. Users
connect to node with the IP address of the package they wish to use.
Each node has a stationary IP address associated with it, and each
package has an IP address associated with it.
Figure 3-5 Before Package Switching