Virtualization 4 of 4 – Networking

Virtual LAN (VLAN) Although VLAN emerged before virtualization and is not part of virtualization topic. I’d just like to start from here as a refresher. Suppose we have computers from finance department and computers from sales department all connected to a single layer-2 switch. There are at least three problems: 1) too many devices on … Read moreVirtualization 4 of 4 – Networking

Virtualization 2 of 4 – Graphics Computing

We covered hypervisor in previous post. In this article we focus on the virtualization of graphics computing resource. GPU vs CPU GPU is a specialized type of microprocessor primarily designed for quick image rendering. GPU appeared as a response to graphically intense applications that put a burden on the CPU and degrated computer performance. They … Read moreVirtualization 2 of 4 – Graphics Computing

Balloons steal memory from virtual machines

I came across an ElasticSearch server (ESXi guest with 32GB physical memory) where the main process keeps dying of OOM. Even worse, after the OOM event, the free memory left is about 10G and Elastic Search cannot start because its JVM is set with -Xms16g in /etc/elasticsearch/jvm.options. So I need to address the OutOfMemory error. … Read moreBalloons steal memory from virtual machines

Overview of vSphere

This post is a summary of VMware’s white paper Introduction to VMware vSphere. ESXi is the hypervisor (virtualization layer) on bare metal servers that abstracts processor, memory, storage and networking resources into multiple virtual machines. It was previously known as ESX and VMware discontinued ESX at version 4.1 so only ESXi is provided at and … Read moreOverview of vSphere