azouhr
When I was looking for a solution that could provide High Availability for two Datacenters, the only solution that remained viable and comprehensible for me was using Corosync/Pacemaker. The reason that I actually need this is, that Mainframe environments typically use two Datacenters, since z/OS...
azouhr
During my works on Kubernetes on Linux on Z and the creation of https://github.com/azouhr/pgtwin, I came across the same issue that most admins have to solve in two-node clusters. How can I get quorum, and what node is to be the primary. While using additional techniques like providing a second...
azouhr
in the previous blog pgtwin — HA PostgreSQL: VM Preparation we setup two VMs with KVM to prepare for a HA PostgreSQL setup. Now, we will configure the Corosync cluster engine, prepare PostgreSQL for synchronous streaming replication and finally configure Pacemaker to provide high availability....
azouhr
This year, I had the task of setting up a Kubernetes environment on a Linux Partition on a s390x system. At first sight, this sounds easy, there are offerings out there that you can purchase. The second look however can make you wonder. There is a structural mismatch between typical Linux on Z...
azouhr
Virtualization systems like KVM, Xen, or z/VM offer the possibility to move running guests from one physical server to another one without service interruption. This is a cool feature for the system administrator because he can service a virtualization host without shutting down any workload on...
azouhr
The standard method to access z/VM is using a 3215 terminal with a terminal emulator. With linux, the x3270 package provides a free emulator for these terminals. One of the features of z/VM is, that you can define several consoles for a guest. This is very helpful if there are problems with a...