Author Archives: George Valentin Voina

#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 »

#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 »