Monthly Archives: October 2010

Exadata cloning using sun ZFS storage appliance snapshots

Oracle Customers often prefer, the ease of use of using system snapshots (Think Emc clarion, Snapview, Snapshots), for cloning databases. Oracle Sun Zfs storage Appliance has infiniband connectivity and storage snapshot capabilities that can be leveraged to efficiently create database clones.

Oracle has a new white paper that outlines the steps  and best practices to use Dataguard in conjunction with the Zfs storage appliance to create database clones using snapshotting technology. This method can also be used with the oracle exadata database machine, keeping in mind a couple of ceavats that are outlined in the white paper.

The white paper can be found at http://www.oracle.com/technetwork/database/features/availability/maa-db-clone-szfssa-172997.pdf

Installing cx-oracle with 11.2.0.2 on ubuntu

cx_Oracle is a Python extension module that allows access to Oracle databases and conforms to the Python database API specification. Below are the steps i used to setup cx_Oracle, with 11.2.0.2, python 2.6 on Ubuntu 10.04 (Lucid Lynx).

1) Installed Oracle 11.2.0.2 Enterprise Edition on Ubuntu (You can also configure this by just installing the 11.2.0.2 instant client too)

2) Download cx_Oracle Source code from http://cx-oracle.sourceforge.net/

3) Install python-dev on ubuntu (Or else you will get compile errors (Like file Python.h not found) when you try to install cx-oracle)

– sudo apt-get install python-dev

4) Login as root

5) export ORACLE_HOME=/u01/11gr2/db_1;export LD_LIBRARY_PATH=$ORACLE_HOME/lib:$LD_LIBRARY_PATH

6) cd <dir-where-cx-oracle-untarred>/cx_Oracle-5.0.4

7) python setup.py install

Once it is installed you can run the sample program from http://wiki.oracle.com/page/Python to make sure it works.

11.2.0.2 Grid infrastructure, private interconnect bonding new feature HAIP

I have been heads down on an Exadata Poc , and only now, got a chance to browse through the new features in 11.2.0.2. The out of place upgrade feature looks interesting.

This new feature in grid infrastructure installation had me really overjoyed (Anyone who has had the pleasure of configuring IPMP, Auto Port Aggregation, Etherchannel etc (based on the o/s) and setting it up correctly to work with Rac, will understand my Joy) . Starting with 11.2.0.2 you do not have to bond the interfaces (If you have redundant GigE nics you are going to use for your private interconnect) you are going to use as the private interconnect. If you have two different interface names to be used for the private interconnect you can provide both the interface names to the oracle grid infrastructure installer and oracle clusterware will create a Highly Available IP Address (HAIP).

Oracle Clusterware, Rac and ASM uses these  load balanced highly available interfaces for communication.

Details can be read at http://download.oracle.com/docs/cd/E11882_01/install.112/e17212/prelinux.htm#BABJHGBE for Linux.

HAIP info can also be found in the 11R2 Clusterware white paper.

Julian Dyke has a blog post that says that MULTICAST has to be enabled for the Network interfaces to enable this to work.

Enabling multicast on the interconnect network is a requirement with 11.2.0.2 Rac.My Oracle Support Notes 1228471.1,1212703.1 details how Multicast can be enabled and checked.