Changing the Hostname and IP Address on a CentOS server and re-configuring Oracle and ORDS

I use VirtualBox quite a lot. Rather than going through the rigmarole of installing the software I need every time I want a new environment, I simply clone the VM I’ve already installed everything on.
One drawback with this approach is that, because I’ve already configured the network settings on this baseline VM, I can’t run two clones concurrently as they both have the same hostname and IP address.

What I’ll be covering here is :

The approach I’ve taken is to execute each step on the command line without the need for any interactive input. Therefore, it’s possible to take the steps described here as building blocks for a bash script (or scripts) to accomplish these tasks.
The exception is where I edit the contents of files. If you wanted to automate this, you can use something like…

sed -i s/192.168.56.220/192.168.56.225/g file_to_edit

…for the IP address and…

sed -i s/frea./rincewind./g file_to_edit

…for the hostname where file_to_edit is the file you want to change.

If you’ve found your way here in search of simply changing the hostname and/or the IP address on a CentOS7 server, then you can just skip all the database related stuff and start right here.

By the way, I’ve decided upon a new naming convention for my servers which makes use of Discworld characters. There may be the odd reference to this in what follows…

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Troubleshooting Oracle 10g XE Installation on Ubuntu

You’ve followed the instructions, everythings working fine. You shutdown your machine and go for a celebratory pint / cup of tea / curry.
Then, when you next start your machine, Oracle doesn’t want to know. What’s going on ?
To be honest, I don’t know. What I do know is that there are some steps you can take to at least attempt to diagnose your problem.

Before I go any further, I’d like to dedicate this post to Wayne.
He found himself in this position. After much head scratching between the two of us, he managed to find and resolve his problem.

Whilst a hardened veteran in computing terms, Wayne was new to both Linux and Oracle. From the mails I’ve received regarding this post, there seem to be a number of people in a similar position to him. Therefore, this post is written with these interpid souls in mind and I’ve tried to take time out to explain why we’re doing stuff at each step.

Update

It’s now quite a while since I posted this and some people have contributed some really useful comments. These include solutions that they found to various problems, which are additional to the ones in this post. So, if you’re still having problems, check out the comments as well. MestreLion’s tip about sudo chmod -t /var/tmp/.oracle seems to be a particularly good example of this.

One other point worth mentioning is that Oracle 11gXE is now available. Many of the issues in this post are still relevant. However, if you’d like to know how to install the latest XE on Ubuntu or Mint, here are the instructions
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