Architecture considerations and best practices for architecting an Oracle RAC solution with Serviceguard and SGeRAC

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Storage Mapping
The Storage Mapping feature enables the mapping of data files to physical devices. Access to
mapping information allows for a detailed understanding of the storage hierarchy in which files
reside. This information is critical to effectively evaluating I/O performance.
The VERITAS Storage Mapping option supports the set of storage APIs called Oracle Mapping
(ORAMAP) that lets Oracle determine the mapping information for files and devices.
Oracle provides a set of dynamic performance views (v$ views) that show the complete mapping of a
file to intermediate layers of LVs and physical devices. These views enable you to locate the exact disk
on which any specific block of a file resides. You can use these mappings along with device statistics
to evaluate I/O performance.
The mapping can be viewed either via Oracle Enterprise Manager GUI or via VERITAS Enterprise
Administration GUI.
Best practices when using CFS for RAC
In an RAC environment, CFS can be used as storage for all kind of files:
• Oracle Clusterware software and configuration files. This is referred to as ORA_CRS_HOME.
• Oracle Clusterware data files: Voting Disk and OCR.
• Oracle RAC software and configuration files. This is referred as ORACLE_HOME.
• Oracle RAC database data files, control files, and archive log files.
However, if a rolling upgrade of Oracle software is needed, use local file systems for
ORA_CRS_HOME and ORACLE_HOME, as shown in the following figure 9.
Figure 9: Oracle RAC and Serviceguard CFS Alternative for Oracle RAC software
Server 1
CFS
shared storage
CFS/CVM
DB Accelerator (ODM)
Oracle RAC
instance 1
SGeRAC
Serviceguard
CFS/CV
DB Accelerator (ODM)
Oracle RAC
instance 2
SGeRAC
Serviceguard
/cfs -
redo logs
/ cfs - crs dat
/ cfs - control files
/cf - data files
/cfs -
archive redo logs
Server 2
/ORACLE_HOME (binaries, etc)
/ORA_CRS_HOME
/ORACLE_HOME
/ORA_CRS_HOME