Monthly Archives: November 2012

Oracle Database Corruption; Identify and Correct

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For DBAs running production databases on professional grade storage systems, corruptions are rare. Indeed EMC arrays include additional technology to actively prevent silent data corruption and bit rot.

However corruption does still occur for a number of different reasons, including hardware failure, software error and sometimes user error. When it does occur, knowing how to properly identify the affected objects, and how in some cases to rescue usable data, can be important time savers to the production Oracle DBA.

In the following post we look at a step by step approach to isolating corruption, verifying it, and then rescuing what data we can. The following was tested on Oracle 10.2.0.2 on a Windows platform.

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Installing Oracle 11.2.0.3 on CentOS 6.3 on VMware Workstation 8.

Posted on by • Posted in ASM, Linux, Oracle, VMware • Tagged , , , , , , , • 8 Comments

In this blog post, we are going to install Oracle 11.2.0.3 64-bit on CentOS 6.3 using VMware Workstation 8. Given that Oracle no longer offers ASMLib for non Oracle branded Linux, we are going to use UDEV rules to manage the disk presentation to ASM.

In my 10-part post on installing Oracle RAC on VMware Workstation I deliberately used an excessive number of screen shots to guide readers through the process. This time I am going to assume you are already comfortable with the Oracle GUI installers, and will skip over excess details to condense this down into a single blog post.

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Using Oracle HCC Compression on VMware Workstation without Exadata or ZFSSA disk

Posted on by • Posted in ASM, Hacking, Linux, Oracle, VMware • Tagged , , , , , • 2 Comments

Hybrid Columnar Compression is one of the new features that Oracle has been touting to persuade DBAs on the virtues of their Exadata and ZFSSA storage solutions.

As stated in my bio, I currently get paid by EMC, but this blog post is not another critique of Oracle sales massaging technical numbers on the assumption that you can use HCC for OLTP loads.

Rather, this is a USE AT YOUR OWN RISK method to explore what HCC can and cannot do. Using this method will render your databases unsupported by Oracle and you must NOT do this on any production or mission critical system. Please note I accept no responsibility for anyone destroying critical data from trying any of this.

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scsi_id on CentOS 6 on VMware returns null

Posted on by • Posted in ASM, Linux, Oracle, VMware • Tagged , , , , , • 3 Comments

You may find the scsi_id command returns a null result in CentOS 6 or RHEL 6 on VMware.

[root@localhost ~]# scsi_id -g -u -d /dev/sdb
[root@localhost ~]#

 
The problem here is that VMware Workstation does not provide unique SCSI identifiers to the virtual SCSI devices. We need to modify the VMX file to make this happen by adding the following directive:

disk.EnableUUID = "TRUE"

 
Restart the VM and now the scsi_id command should work:

[root@localhost ~]# scsi_id -g -u -d /dev/sdb
36000c2980c56d98cc5150a0ac103058d

11gR2 Grid install – clscfg.bin: error while loading shared libraries: libcap.so.1: cannot open shared object file

Posted on by • Posted in ASM, Linux, Oracle • Tagged , , , , , • 3 Comments

You are installing 11gR2 11.2.0.1 Grid Infrastructure on Red Hat 6, CentOS 6 or similar Linux operating system, and right at the very end of the process, the root.sh script blows up with a really odd error:

[root@localhost oraInventory]# cd /u01/app/oracle/product/11.2.0/db_1
[root@localhost db_1]# ./root.sh
Running Oracle 11g root.sh script...

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Oracle 11gR2 2-node RAC on VMware Workstation 9

Posted on by • Posted in Linux, Oracle, RAC, VMware • Tagged , , , , • 1 Comment

Last week I was in Dallas, Texas meeting with some customers and reminding myself what sunny weather looks like.

I took the opportunity to hook up with my friend and colleague Lester Wells, an awesome EMC guy based out of Dallas, and who is also an expert in all things Oracle.

Sitting in the Champps bar near to DFW, we decided, as geeks are often want to do, to see if the 11gR2 RAC on VMware Workstation 8, the process for which is shown in this blog, would also work under Lester’s VMware Workstation 9.

Two guys, two laptops, a table close to wall sockets and more than just a few beers later, happily it turns out that everything worked exactly the same under Workstation 9, as it did under Workstation 8.

If you’re running under Workstation 8 you can go ahead and upgrade, it won’t break anything.

If you are wishing to create a RAC under your Workstation 9, the ten part process will work just the same.