Author Archives: George Valentin Voina

#Regional Participation Within #European Multi-Level #Governance

By | July 24, 2017

I am pleased to make some promotion for the new book of my wife, that deals with European politics. Interesting and complicated stuff from the world of European Governance. ” Why does the region of Saxony-Anhalt participate in the European Multi-Level Governance system and how does this occur? This book provides an account of the… Read More »

Portable #Docker #Swarm made of #RaspberryPI

By | October 12, 2017

This is the new cool thing to build at home. A small cluster made of Raspberry PIs. Hardware setup of the cluster ITEM 1: Raspberry Pi 3 Model B I went for a set of 5 PIs because of the greater flexibility when you get more machines. I hope to be able to test several… Read More »

#Docker volumes and Selinux

By | September 30, 2017

When running complex environments on Docker on Linux again we face the mighty selinux. There are plenty of selinux alerts generated when I start my environment when the host machines have selinux enabled and volumes are used by the containers. Setting selinux permissions is hard and tedious and many people just prefer to disable it.… Read More »

Validate and Investigate a live #DRBD replicated Oracle Instance using LVM clone

By | October 19, 2017

This is another post related to the DRBD replication setup I describe in post #DRBD based disk replication of a production cluster to a remote site cluster on RHEL 6. Sometimes we need to be able to mount the offline replicated Oracle database instance for investigations. This can be done by using logical volume snapshots.… Read More »

Hidden Oracle dependencies when running under #Docker on Fedora/CentOS/RedHat Linux

By | June 28, 2017

There are some hidden dependencies of running oracle database in a docker container under Fedora/CentOS/RedHat Linux. STEP 1: Kernel parameters Because the Oracle engine from the Docker container uses in fact the kernel of the host machine we cannot escape the need to set up some kernel parameters on the host. On the host machine… Read More »

#SMB Breaking News: #HPE #MicroServer Gen10

By | June 12, 2017

Finally a new release of the HPE MicroServer updated at the new generation Gen10. HPE ProLiant MicroServer Gen10 It seems that the Gen8 release of the MicroServer was so successful (I am the proud owner of 3 HP MicroServer Gen8) that HPE never released a Gen9 model. What are the main updates after a quick… Read More »

Get over it: The #Cloud is always someone-else computer.

By | June 1, 2017

I read another article on a popular geek site on how the Cloud is the new normal and how odd you are if you have something against it. My take on it is that an intelligent IT professional is not to take this things lightly. There are several topics one has to consider when deciding… Read More »

How to evaluate your website from security/performance/value PoV

By | June 11, 2018

The issue of making a correct evaluation of a web site is one that should be addressed by any site owner at some point. The most important metrics of a web site that are a must will be discussed bellow. SECURITY I do not know how to stress the importance of this metric. This is… Read More »

Linux: Save a pdf presentation to individual image slides

By | May 26, 2017

There is a very simple way to save a pdf presentation to individual jpeg images of the slides using convert. convert -density 300 presentation.pdf presentation_page_%04d.jpg where: – density 300 specifies the DPI used to read the pdf. – presentation_page_%04d.jpg is a name pattern for the saved images As a result if presentation has 20 slides… Read More »

#Docker #Jboss dies with java.lang.OutOfMemoryError: Metaspace after several redeploys

By | May 26, 2017

There is an annoying issue with a Jboss EAP 7 Docker container I am using. After 3 deploys of my ear package I hit the “java.lang.OutOfMemoryError: Metaspace” issue. According to RedHat Solution 2038983 this is a known issue caused by: Root Cause The Metaspace is being exhausted. Either it is undersized, or there is a… Read More »