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 »
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 »
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 »
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 »
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 »
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 »
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 »
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 »
It seems that now I have a name for what I have doing for the last 15 years 🙂 I attended a a DevTalks conference and the hype of the day was the DevOps idea. According to the wiki definition: DevOps (a clipped compound of “software DEVelopment” and “information technology OPerationS”) is a term used… Read More »
A very important release announced in a post on the Oracle blog. Java SE support for Docker CPU and memory limits In short: “As of Java SE 8u131, and in JDK 9, the JVM is Docker-aware with respect to Docker CPU limits transparently.” SET 1: If -XX:ParalllelGCThreads, or -XX:CICompilerCount are not specified as command line… Read More »