IBM SG24-5131-00 Manuale Utente
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IBM Certification Study Guide AIX HACMP
reintegration, a node remains as a standby and does not take back any of the
resources that it had initially served.
resources that it had initially served.
Concurrent Resource Groups: A concurrent resource group may be shared
simultaneously by multiple nodes. The resources that can be part of a
concurrent resource group are limited to volume groups with raw logical
volumes, raw disks, and application servers.
simultaneously by multiple nodes. The resources that can be part of a
concurrent resource group are limited to volume groups with raw logical
volumes, raw disks, and application servers.
When a node fails, there is no takeover involved for concurrent resources.
Upon reintegration, a node again accesses the resources simultaneously with
the other nodes.
Upon reintegration, a node again accesses the resources simultaneously with
the other nodes.
The Cluster Manager makes the following assumptions about the acquisition
of resource groups:
of resource groups:
Cascading
The active node with the highest priority controls the
resource group.
resource group.
Concurrent
All active nodes have access to the resource group.
Rotating
The node with the rotating resource group’s associated
service IP address controls the resource group.
service IP address controls the resource group.
2.4.2 Shared LVM Components
The first distinction that you need to make while designing a cluster is
whether you need a non-concurrent or a concurrent shared disk access
environment.
whether you need a non-concurrent or a concurrent shared disk access
environment.
2.4.2.1 Non-Concurrent Disk Access Configurations
The possible non-concurrent disk access configurations are:
The possible non-concurrent disk access configurations are:
• Hot-Standby
• Rotating Standby
• Mutual Takeover
• Third-Party Takeover
Hot-Standby Configuration
Figure 2 illustrates a two node cluster in a hot-standby configuration.
Figure 2 illustrates a two node cluster in a hot-standby configuration.