High availability requires the following hardware and system components:
Two homogenous, network systems, with similar configurations in terms of resources like CPU, memory, and so on. See Chapter 2, “What is High Availability?,” for the installation configuration.
You should also install the VCS graphical user interface to facilitate configuration and administration.
The resource type HAase, imported into the VCS.
Access to shared multihost disks, which store the databases for the Adaptive Server configured for high availability.
Veritas Volume Manager 3.1 or later to manage disks and create resources like DiskGroup and Volume.
Third-party vendor mirroring for media failure protection.
A service group on each system. A service group is a set of resources that provides a specific service. To provide a service for an Adaptive Server that is configured for high availability, the service group should include such resources as DiskGroup, Volume, Mount, IP, NIC, and HAase for Adaptive Server. A sample service group and the resource dependency graph is shown in Figure 11-1. See the Veritas Cluster Server User’s Guide for more information on how to create a service group and how to add resources to a service group.
Each service group must contain at least two resources
with one resource of type HAase. Use the cluster
command to establish resource dependency so that the resource of
type HAase depends on the other resources.
Both public and private networks on both the nodes.
See your hardware and operating system documentation for information about installing platform-specific high availability software.
In Figure 11-1, the configuration of the service group has one DiskGroup, syb_vrtsdg1, on which four volumes are created. One volume is for the Adaptive Server installation, one is for databases that are created on the file system, and the other two are for databases created on raw devices. The two mount resources are created for file system of type ufs layering on the volume resources. The resource, syb_ase150 of type HAase is the Adaptive Server installation, which sits on top of the mount resources. syb_ase150 also requires resource IP, which also requires resource NIC for public network access.
Not shown in Figure 11-1, the service group SybASE running on the primary node and service group, SybASE2 running on the secondary node, with a similar configuration:
Figure 11-1: Sample service group running on Veritas Cluster Server
