Category Archives: DataCenter

Portable #RaspberryPI #Docker #Swarm – Static IP, Ethernet based, #Portainer

By | October 14, 2017

As I discussed in post Portable #Docker #Swarm made of #RaspberryPI – Updated hardware there were several hardware updates done to the swarm. One of the updates was adding a switch and connecting all the Raspberry PIs to the switch. First version of the Docker Swarm was done using the wifi connections of the PIs.… Read More »

Portable #Docker #Swarm made of #RaspberryPI – Updated hardware

By | October 14, 2017

I wanted to update my hardware setup for the Docker Swarm cluster from post Portable #Docker #Swarm made of #RaspberryPI. The idea was to make it more portable, more reliable and a bit faster. The following steps were done: Add ethernet support The original setup used a small Edimax router with the Raspberry Pi nodes… Read More »

#nginx proxy_pass an URI to another server with a different URI

By | August 22, 2017

Nginx can be used very nicely to aggregate resources after the same fronted by using it as a proxy. I want my set-up to be like: URL1: https://blog.voina.uk -> nas1 hosted wordpress URL2: https://blog.voina.uk/store -> nas2 hosted store with URL https://nas/store URL3: https://blog.voina.uk/doc -> nas4 hosted wiki with URL https://nas4/wiki How can we do this… Read More »

#DRBD: Synchronization of sites after the connection between sites is down for a long time

By | August 10, 2017

In a DRBD setup as described in #DRBD based disk replication of a production cluster to a remote site cluster on RHEL 6 there is a special case when due to some external issues the communication line between the sites is down due to technical reason for a longer period of time (days). The line… 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 »