Veritas Storage Foundation 5.1 SP1 for Oracle RAC Administrator"s Guide (5900-1512, April 2011)

Figure 1-3
Data stack
Databases
containing:
Node 1
Node 2
Data
flow
Data
flow
Disk I/O
Disk I/O
CVM
CFS
ODM
LGWR
ARCH
CKPT
DBWR
CVM
CFS
ODM
Control
Files
Redo Log
Files
Datafiles
Temp
Files
Oracle RAC
Instance
LGWR
ARCH
CKPT
DBWR
Oracle RAC
Instance
Communication requirements
End-users on a client system are unaware that they are accessing a database
hosted by multiple instances. The key to performing I/O to a database accessed
by multiple instances is communication between the processes. Each layer or
component in the data stack must reliably communicate with its peer on other
nodes to function properly. RAC instances must communicate to coordinate
protection of data blocks in the database. ODM processes must communicate to
coordinate data file protection and access across the cluster. CFS coordinates
metadata updates for file systems, while CVM coordinates the status of logical
volumes and maps.
Figure 1-4 represents the communication stack.
Overview of Veritas Storage Foundation for Oracle RAC
Component products and processes of SF Oracle RAC
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