Oracle Database 18c: Documentation released!

Today i surfed to and there i found the documentation for oracle database 18c:

In march 2018 i wrote about the new installation procedure of oracle database 18c via rpm, which was announced inside the "new features".

The installation guide for Linux contains now the commands for installing the database via rpm. Here a screencopy of chapter 11:
 rpm -ivh oracle-ee-db-
This command creates the (more...)

Docker on Fedora 27

This walks you through the steps to install the Community Edition of Docker on Fedora 27. If you’ve been living under a rock for a few years, Docker is an open source container virtualization software.

Docker or Docker Community Edition is a necessary step if you want to install something like Microsoft’s SQL Server on Fedora because only these are supported platforms:

  • Red Hat Enterprise Linux 7.3 or 7.4
  • SUSE Linux Enterprise Server (more...)

Ubuntu 16.04: Installation of chrome-browser fails with libnss3 (>= 2:3.22) [2]

The first solution for installing google-chrome after getting the error
dpkg: Abhängigkeitsprobleme verhindern Konfiguration von google-chrome-stable:
 google-chrome-stable hängt ab von libnss3 (>= 2:3.22); aber:
  Version von libnss3:amd64 auf dem System ist 2:3.21-1ubuntu4.

dpkg: Fehler beim Bearbeiten des Paketes google-chrome-stable (--install):
 Abhängigkeitsprobleme - verbleibt unkonfiguriert
was to install chromium (see this posting).

But now i know, what the problem was:
Inside /etc/apt/sources.list the entry:
deb xenial-security restricted main (more...)

OSWatcher, Tracefile Analyzer, and Oracle RAC 12.2

When I started the series about Tracefile Analyzer (TFA) I promised three parts. One for single instance, another one for Oracle Restart and this one is going to be about Real Application Clusters. The previous two parts are published already, this is the final piece.

The environment

I am using a virtualised 2-node cluster named rac122pri with nodes rac122pri1{1,2} based on Oracle Linux 7.4. RAC is patched to I (more...)

Quick install of prometheus, node_exporter and grafana

This blogpost is a follow up of this blogpost, with the exception that the install method in this blogpost is way easier, it uses an Ansible playbook to do most of the installation.

1. Install git and ansible via EPEL:

# yum -y localinstall
# yum -y install ansible git

2. Clone my ‘prometheus_node_exp_grafana_install’ repository:

# git clone

3. Run the prometheus.yml playbook to install (more...)

Oracle database wait event ‘db file async I/O submit’ timing bug

This blogpost is a look into a bug in the wait interface that has been reported by me to Oracle a few times. I verified all versions from Oracle 11.2 version up to on Linux x86_64, in all these versions this bug is present. The bug is that the wait event ‘db file async I/O submit’ does not time anything when using ASM, only when using a filesystem, where (more...)

All about ansible vault

This blogpost is about using ansible vault. Vault is a way to encrypt sensitive information in ansible scripts by encrypting it. The motivation for this blogpost is the lack of a description that makes sense to me of what the possibilities are for using vault, and how to use the vault options in playbooks.

The basic way ansible vault works, is that when ansible-playbook reads a yaml file, it encounters $ANSIBLE_VAULT;1.1;AES256 indicating ansible vault (more...)

A re-introduction to the vagrant-builder suite for database installation

In a blogpost introducing the vagrant builder suite I explained what the suite could do, and the principal use, to automate the installation of the Oracle database software and the creation of a database on a virtual machine using vagrant together with ansible and virtual box.

This blogpost shows how to use that suite for automating the installation of the Oracle database software and the creation of a database on a linux server directly, with (more...)

Virtualbox: failed & Run ‘make oldconfig && make prepare’

After updating to ubuntu 18.04 i had to reinstall virtualbox:

# dpkg -i virtualbox-5.2_5.2.10-122088~Debian~stretch_amd64.deb 
Vormals nicht ausgewähltes Paket virtualbox-5.2 wird gewählt.
(Lese Datenbank ... 378316 Dateien und Verzeichnisse sind derzeit installiert.)
Vorbereitung zum Entpacken von virtualbox-5.2_5.2.10-122088~Debian~stretch_amd64.deb ...
Entpacken von virtualbox-5.2 (5.2.10-122088~Debian~stretch) ...
virtualbox-5.2 (5.2.10-122088~Debian~stretch) wird eingerichtet ...
addgroup: Die Gruppe »vboxusers« existiert bereits als Systemgruppe. Programmende. failed: Look at /var/log/vbox-install. (more...)

Ruby GEM Mongo

While trying to use the Ruby gem utility to install the MongoDB gem, I encountered an error on a new Fedora 27 instance. This is the error message:

Fetching: bson-4.3.0.gem (100%)
Building native extensions.  This could take a while...
ERROR:  Error installing mongo:
        ERROR: Failed to build gem native extension.

    current directory: /usr/local/share/gems/gems/bson-4.3.0/ext/bson
/usr/bin/ruby -r ./siteconf20180517-49401-1htl7zc.rb extconf.rb
mkmf.rb can't find header files for ruby at /usr/share/include/ruby.h


MongoDB on Fedora 27

I was very pleased to see MongoDB 3.4 in the repo for Fedora 27; however, I was quite frankly severely disappointed by the lack of concrete installation steps in the MongoDB in Action, Second Edition. The installation is straightforward as long as you remember that you don’t simply install a mongodb package. You need to install the mongodb and mongodb-server packages as well as some dependents.

As the root user, you can use yum (more...)

MySQL on Fedora 27

While updating my class image to Fedora 27, I noticed that it installed the Akonadi Server. The documentation on the Akonadi server lacked some straightforward documentation. It also offered a bundled set of software that limited how to approach MySQL development.

So, I removed all those packages with the following syntax:

dnf remove `rpm -qa | grep akonadi`

After removing those Akonadi packages, I installed the MySQL Community Edition from the Fedora repo with this (more...)

PostgreSQL Calling File

Somebody asked: How do you run a script file from PostgreSQL’s psql prompt? I created two files to answer the question. Here are the two files:

Static File

SELECT 'Hello World!';

Dynamic File

SELECT 'Hello ['||current_user||']!';

It’s a simple solution, you put a \i or \include before the script file name, like:

\i helloworld.sql


\include hellowhom.sql

I hope this helps those trying to call SQL script files from an interactive psql session.

Ubuntu 16.04: Installation of chrome-browser fails with libnss3 (>= 2:3.22)

On my old laptop with ubuntu 16.04 i tried to install "chrome-browser":
# dpkg -i google-chrome-stable_current_amd64\ \(1\).deb 
Vormals nicht ausgewähltes Paket google-chrome-stable wird gewählt.
(Lese Datenbank ... 137351 Dateien und Verzeichnisse sind derzeit installiert.)
Vorbereitung zum Entpacken von google-chrome-stable_current_amd64 (1).deb ...
Entpacken von google-chrome-stable (64.0.3282.186-1) ...
dpkg: Abhängigkeitsprobleme verhindern Konfiguration von google-chrome-stable:
 google-chrome-stable hängt ab von libnss3 (>= 2:3.22); aber:
  Version von libnss3:amd64 auf dem System ist 2:3.21-1ubuntu4.


Setup PostgreSQL

After you have installed PostgeSQL on Fedora and initialized the database, you have several steps to configure a new instance. This blog post shows you how to create all the implementation pieces for a student database.

Connect as the postgres user from a sudoer user. It requires you to connect as the root user before you connect as the postgres user.

sudo sh

As the root user, you don’t need a password to connect as (more...)

Fedora Install PostgreSQL

The following shows you the install of PostgreSQL 9.6 on Fedora 27. You either use the sudoer privileges as a user in the sudoer group, or by using the su command to become the root user:

sudo yum install -y postgres*

It should display the following installation:

Last metadata expiration check: 2:22:55 ago on Sat 12 May 2018 02:48:53 PM MDT.
Package postgresql-libs-9.6.8-1.fc27.x86_64 is already installed, skipping.
Dependencies resolved.

Enabling SFTP-only access on Linux

Recently I had the need to share a zip file with a bunch of people that was big enough not to fit into email anymore. So I wanted to get it onto my server so that folks could grab it via SFTP from there. SFTP is setup by default on my Linux environment, so them … Continue reading "Enabling SFTP-only access on Linux"

Installing haveged from Oracle repositories

In my previous blog, I mentioned the installation of the utility Haveged that is used to increase your entropy on non-gui systems. Since you can download it from the Oracle yum repository, I figured that I could install it from yum too, instead of using rpm. This prevents me from having to download it myself, and ensures I have the one that is applicable to my version of Linux.

Too bad it isn't (more...)

Base box ready? Let’s create a box!

Last week I wrote about creating our own Vagrant base box, based on the new and fresh Oracle Linux 7 Update 5. As a reaction on my article I got noted that Oracle also keeps base boxes for their latest linuxes at They're also a great start.

To begin, I created a project structure for all my vagrant projects:
As you can see, I have a vagrant main projects folder on my (more...)

Oracle Linux 7.5 released ?!

Oracle released its Linux in version 7.5 without a announcement on their webpages. If you ask google
oracle linux 7.5
you will be directed to this site:

But with the right search string you can find Oracle Linux 7.5 inside

The new features can be found here:
or here: