Database Reference
In-Depth Information
As shown in Figure
4-5
, a Flex ASM consists of three kinds of Oracle ASM configurations:
1.
Local Oracle ASM Clients: Oracle database instances such as those on nodes 1, 2, and
3 access the local ASM instances on the same node. In this case, these Oracle database
instances have direct I/O access to the ASM disks in the shared storage and also access the
Oracle ASM metadata in the local ASM instance. This configuration is same as for the ASM
in 11gR2 or before.
2.
Flex ASM Clients: Oracle database instances such as the one on node 4 have to connect to
a remote ASM instance running in another node. This remote ASM instance is the ASM
instance on node 1 in Figure
4-5
.
3.
Oracle ACFS and ADVM through Oracle ASM proxy instance: In Flex ASM configuration,
Oracle ASM proxy is introduced to provide support for Oracle ACFS and Oracle ASM
Dynamic Volume Manager (Oracle ADVM). Figure
4-6
shows the architecture of such
a configuration. On the left node, the ACFS and ADVM talk to the ASM proxy instance,
which connects to the local ASM instance. On the right node, the ACFS and ADVM
connect to the ASM proxy instance, which connects to the remote ASM instance that is
located in the left node, as the right node doesn't run local ASM instance.
ADVM/
ACFS
ADVM/
ACFS
Database
Instance
ASM Proxy
ASM Proxy
Grid Infrasturecture
Grid Infrasturecture
ASM
Instance
Clusterware
Clusterware
ASM Disk
Groups
Figure 4-6.
ASM proxy for Oracle ACFS and Oracle ADVM
In order for Flex ASM clients to connect to remote ASM instances, Flex ASM introduces a new type of network
called the ASM network between Flex ASM clients and ASM instances. With this new type of network, inside of Oracle
Clusterware 12c, there are four types of networks:
1.
Public network, which usually connects the cluster nodes to the Corporate network;
2.
Private network for the interconnect communication between the cluster nodes;
3.
ASM network for ASM clients to connect to ASM instances;
4.
Storage network for the cluster nodes to access the shared storage.
ASM network is needed only for a Flex ASM configuration.
