Filter
Top Products
Integrations with Other Applications
Cluster Integrations with Data Protector
Chapter 13 615
all cluster nodes. Each cluster node compares this packet and determines
which cluster node is still operational so that appropriate ownership of
the package (MC/SG, Veritas Cluster) or group (MSCS) can be
determined.
What is a Package
or Group?
A package (MC/SG, Veritas Cluster) or a group (MSCS) is a collection of
resources that are needed to run a specific cluster-aware application.
Each cluster-aware application declares its own critical resources. The
following resources must be defined in each group or package:
• Shared disk volumes (MSCS)
• Shared volume groups (MC/SG, Veritas Cluster)
•Network IP names
• Network IP addresses
• Cluster-aware application services
What Is a Virtual
Server?
Disk volumes and volume groups represent shared physical disks. A
network IP name and a network IP address are resources that define a
virtual server of a cluster-aware application. Its IP name and address
are cached by the cluster software and mapped to the cluster node on
which the specific package or group is currently running. Since the group
or package can switch from one node to another, the virtual server can
reside on different machines in different time frames.
What Is a
Failover?
Each package or group has its own preferred node on which it normally
runs. Such a node is called a primary node. A package or group can be
moved to another cluster node (one of the secondary nodes). The process
of transferring a package or group from the primary cluster node to the
secondary is called failover or switchover. The secondary node accepts
the package or group in case of failure of the primary node. A failover can
occur for many different reasons:
• Software failures on the primary node
• Hardware failures on the primary node
• The administrator intentionally transfers the ownership because of
maintenance on the primary node