Installing Oracle XE, ORDS and Apex on CentOS – Part Two: Installation

This is part two in a series of blog posts about how to install Oracle 11g Express Edition (XE) with Oracle Application Express (Apex) on a CentOS Linux server, with Apex served by Oracle REST Data Services (ORDS) running on top of Tomcat and Apache.

Let's get right to it, starting with Oracle XE.

Installing Oracle XE

This is actually quite straightforward, assuming you have followed the prerequisite steps in part one.

As part of (more...)

Using a terminal emulator on Mac

Dumb title for a blog post? No, not really I guess…

ZOC Terminal emulatorI have been using a terminal emulator, basically ever since I got away from the VT100 terminal:

  • ICE.TCP Pro
  • Reflection ‘X’

And a few other obscure applications that I cannot even recall anymore.
Currently, and over the last 6 to 8 years, I have been using ZOC.

The background of this story is: In the beginning these were the first DOS PC’s (more...)

Mac SQL Developer Install

This how you install SQL Developer on Mac OS Yosemite. The first thing you need to do is download and install Java 8, not Java 7 on your Mac OS Yosemite, as suggested on some web sites. You can determine whether or not Java is installed by running the following command:

Mac-Pro-3:~ username$ java -version
No Java runtime present, requesting install.

You must accept the Java license to install Java 8 on the (more...)

Linux Locking using flock

I am faced with a situation on how to creating locking mechanism for RMAN backup.

Script backups database and can be run simutaneously if it’s not for the same database.

Hence sh running for PROD1 & PROD2 at the same time is VALID and running for PROD1 & PROD1 at the same time is NOT VALID.

While is running, (backup archivelog) should not be running.

This was instigated (more...)

Run X11 Apps on Mac

It’s possible folks didn’t notice but Mac OS X no longer includes XQuartz by default from Maverick forward. You need to download XQuartz and install it. I’d recommend after you install Xcode.

Launch XQuartz and then either use the bash shell it opens or open a Terminal bash shell session. Inside the shell, you might start Secure Shell (ssh) like this:

Mac-Pro-3:~ michaelmclaughlin$ ssh student@
student@'s password: 

Fedora X11 Install

While working through getting my Mac OS X to work with X11, I stumbled on some interesting errors and misdirection solutions. Like most things, the solution was straightforward. Then, it struck me that I hadn’t installed it on my Fedora image. This blog post show you the errors I got the way to get it to work, and how to install X11 on Fedora.

The first step requires discovering the package. If you remember xclock (more...)

Installing Oracle XE, ORDS and Apex on CentOS – Part One: Preparation

This is part one in a series of blog posts about how to install Oracle 11g Express Edition (XE) with Oracle Application Express (Apex) on a CentOS Linux server, with Apex served by Oracle REST Data Services (ORDS) running on top of Tomcat and Apache.

Provisioning the server

First of all, we need a server to install the software on. There are many hosting providers that offer cheap Linux servers. I have been trying out (more...)

Installing Oracle XE, ORDS and Apex on CentOS

I am writing a series of blog posts about how to install Oracle 11g Express Edition (XE) with Oracle Application Express (Apex) on a CentOS Linux server, with Apex served by Oracle REST Data Services (ORDS) running on top of Tomcat and Apache.

This is perhaps better explained with an illustration of the setup:

Best of all, this setup consists only of free (license-free) software, and as you will see in this series of blog (more...)

Expand swap using SSM

The mere reason that I dug into SSM yeasterday was that I wanted to install the Oracle Database 12c.

(Did you know yesterday came from the word 'yeast'? So actually yeasterday: because one used the yeast of the day before to bake the bread of today. Also in Dutch  the word for yeast: 'gist', still sounds in the word for yeasterday: 'gisteren'.)

I ran however against the prerequisite check on (more...)

How to configure Link Aggregation Control Protocol on Exadata

During a recent X5 installation I had to configure Link Aggregation Control Protocol (LACP) on the client network of the compute nodes. Although the ports were running at 10Gbits and default configuration of Active/Passive works perfectly fine the customer wanted even distribution of traffic and workload across their core switches.

Link Aggregation Control Protocol (LACP), also known as 802.3ad is a methods of combining multiple physical network connections into one logical connection to increase (more...)

LVM with SSM on OL7

Or how to  encrypt your title with acronyms...

Today I wanted to create a VM with an Oracle SOA/BPM Suite 12c installation, since I'm to give a workshop on the installation of it. I used Oracle Linux 6 for my installations and the last few years I did play around quite a lot with it (for someone who is not a core systems administrator), to upgrade all my VM's to the latest update, remove obsolete (more...)

The Great Hypervisor Bake-off: VMware ESX vs Oracle VM


This is a very simple post to show the results of some recent testing that Tom and I ran using Oracle SLOB on Violin to determine the impact of using virtualization. But before we get to that, I am duty bound to write a paragraph of text featuring lots of long sentences peppered with industry buzz words. Forgive me, it’s just the way I’m wired.

It is increasingly common these days to find database environments running (more...)

No space left on device…

Today I ran into something curious, that I saw a few weeks ago on a training that I gave: the root filesystem  ran full (Oracle Linux 6). At first I did not find anything that caused the problem, but the command 'df -k' indeed suggested a full root filesystem. Using 'du -sh /home/oracle' we found that that folder consumed an unreasonable amount of space. In my case today I found the same. It turns out (more...)

Hey dude, where’s my memory? part 2

In my previous article I started exploring the memory usage of a process on a recent linux kernel (2.6.39-400.243.1 (UEK2)), recent means “recent for the Enterprise Linux distributions” in this context, linux kernel developers would point out that the kernel itself is at version 3.19 (“stable version” at the time of writing of this blogpost).

The previous article showed that every process has its own address space, and that different (more...)

Hey dude, where’s my memory?

This blogpost is about finding the actual amount of memory a process is taking. In order to do so, this post dives into the memory mechanisms of Linux. The examples in this article are taken from an Oracle Linux version 6.6 server, with kernel 2.6.39-400.243.1 (UEK2). This is written with the Oracle database processes in mind, but actually uses examples of a processes running ‘cat’, which means the contents of (more...)

Implementing Linux native multipathing or DM-MPIO together with EMC PowerPath


Guest Post

I’m delighted to say that this is another guest post from my good friend Nate Fuzi, who performs the same role as me for Violin but is based in the US instead of EMEA. Because he is American, Nate thinks that scones are called “biscuits”, that chips are called “fries” and that there is nothing – *nothing* – that cannot be improved with the simple addition of bacon. Clearly, something is fundamentally wrong with him (more...)

Using the Oracle Grid Infrastructure Agents for GoldenGate on Oracle restart

I was testing Oracle Goldengate on a non-clustered Oracle database with ASM. With ASM, you need to have the grid infrastructure installed. The cluster ware for the single node install is called ‘oracle restart’.

The most convenient way to have Goldengate running at startup that I could find, was using the Oracle Grid Infrastructure Agents. These agents are not installed by default, you need to download these from the Oracle Technology (more...)

Oracle system V shared memory indicated deleted

This article is written with examples taken from an (virtualised) Oracle Linux 6u6 X86_64 operating system, and Oracle database version However, I think the same behaviour is true for Oracle 11 and 10 and earlier versions.

Probably most readers of this blog are aware that a “map” of mapped memory for a process exists for every process in /proc, in a pseudo file called “maps”. If I want to look (more...)

Darwin-IT 2015-03-13 11:50:00

I have several Virtual Machines for our Virtual Course Environments. From time to time, I do an upgrade of the Oracle Linux version. But with every upgrade, Oracle Linux leaves the old kernel files. And in time the root disk is cluttered up. So I want to remove the old kernels. With a little googling, I came up with a discussion thread in Oracle Communities: Oracle Linux Remove Old Kernels (Archived by now).

To me (more...)

enabling hardware acceleration for Android SDK emulator on Linux

When using the Android SDK for testing mobile applications (for instance, created with MAF, Mobile Application Framework), you can utilize the GPU for hardware acceleration on the Windows platform. This will greatly improve the performance of the emulator. To be able to use the acceleration, you’ll need to install a separate package called Intel x86 Emulator Accelerator (HAXM installer).

Android SDK Manager Android SDK Manager

If you’re on the Linux platform, you notice that the Status is  “Not (more...)