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If the necessary hardware in
terms of nodes, interconnect, and storage arrays, etc. is already
available, the same infrastructure will be used.
9i-RAC implementation with
Veritas Advance Cluster requires that the shared storage support the
SCSI-3 PR. In this case, it would be important to ensure that the
supporting storage array is used.
The utility vxfentsthdw can be
used to verify that shared storage arrays support SCSI-3 persistent
reservations and I/O fencing. The utility can be used to test one
disk at a time, a set of disks specified in a file, or a disk group.
For Release 3.5 MP1 of DBE/AC
for Oracle9i RAC, disk groups created on shared volumes are not
automatically configured with I/O fencing enabled. To enable I/O
fencing, the shared disk group must be deported and then imported.
If the current database files
are using the Veritas Quick I/O feature, they should be converted to
regular VxFS files before installing VERITAS DBE/AC for Oracle9i RAC,
which uses the ODM (Oracle Disk Manager) interface for high
performance file access.
Remove the earlier version VCS
software and install patches and the new DBE/AC packages. Follow the
Veritas documentation to configure the CVM, CFS, and VCS with
default service groups. Start the cluster and keep it running.
Ensure that DB files are moved
to the CFS based file system. Then, perform the same changes at the
database level as explained in the previous section to move DB files
into a RAC database. These steps convert the single instance
Oracle into a multi-node RAC database.
When the Oracle database
supporting vendor supplied packaged applications is migrated or
converted to a multi-node RAC database, there are specific ways
these applications can utilize the features of the RAC database.
With the multiple instances providing more scalability and high
availability at the database level, the applications need to make
use of such features. The following sections will provide a brief
look at the discipline followed in an application client
In Case of SAP Applications
The server side and client side
configuration changes may include:
Before the database files are
transferred to the target system, verify that the Oracle database on
the existing system is in the right condition for the upgrade.
Specifically for this task, SAP provides two specific SQL scripts to
perform some checks in advance of the Oracle Database 10g database
upgrade. The scripts are called checks.sql and premig.sql and they
can be found on the first RDBMS CD from SAP for Oracle Database 10g
Upgrade SAP Software and
For the correct use of
transparent application failover, the SAP software library dboraslib
must be replaced by a new version. This library is located in the
directory /usr/sap/<SID>/exe/run together with all other executables
for a specific SAP R/3 system. The new version of the library is
compiled using the OCI 8 call interface to access the database,
whereas the original version up to SAP R/3 4.6D was compiled and
shipped using OCI 7 call semantics.
The new dboraslib must be
requested from SAP directly. It is not currently part of any
shipping CD set for release 4.6D. Additionally, it is not available
on SAP?s service market place or through OCS.
The library must be replaced on
all SAP R/3 application servers. Additional SAP R/3 application
servers outside of the database cluster configuration may possibly
use a different operating system.
The Oracle client software for
Oracle9i must also be installed on every additional SAP R/3
application server. The Oracle software version used to build the
shared library, dboraslib, and the installed Oracle client version