Virtualization

Picking a Motherboard and Processor to use with Virtualization

When selecting you hardware, there are many factors to consider; How many Virtual Machines do you want to run at a time? How busy will these Virtual Machines be? If you are getting ready to P2V a bunch of virtual machines, then you should use Perfmon (In a Windows Environment) to take a benchmark before proceeding. In this article, I am not going to focus on sizing your environment, but rather making sure that the hardware you select is going to be compatible with what you want to do. **Note, Read more […]

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Published Applications vs Application Virtualization

Portability of Software is the ability to run the same software on a number of different systems.  One of the goals of many software developers are to be able to write the application once, and run it on as many platforms as possible.  A similar goal of Systems administrators is to ensure you can run software with as few conflicts as possible Typically when one thinks of portability of software in the context of virtualization, two things come to mind, Published Applications and Application Virtualization. Read more […]


Installing and Configuring Kernel Virtual Machines (KVM) on Fedora/Redhat/Centos

KVM Stands for Kernel Virtual Machine. KVM is a virtualization technology built into the Linux Kernel based on QEMU (Quick Emulator) and is used for server virtualization. QEMU allows for virtualizing hardware, all the way from a complete hardware stack to a single device. KVM basically takes QEMU and allows it to use hardware extensions to achieve better performance. KVM is the default hypervisor in the Open Stack project. **Note: This content was ported from our old website. So the information Read more […]


History of Virtualization

When you think of the beginning of Server Virtualization, companies like VMWare may come to mind. The thing you may not realize is Server Virtualization actually started back in the early 1960’s and was pioneered by companies like General Electric (GE), Bell Labs, and International Business Machines (IBM). The Invention of the Virtual Machine In the Early 1960’s IBM had a wide range of systems; each generation of which was substantially different from the previous. This made it difficult Read more […]


Protecting yourself from Spectre and Meltdown

Spectre (CVE-2017-5753 and CVE-2017-5715) and Meltdown (CVE-2017-5754) are exploits in CPU architecture allowing attakers access to protected memory they should not have access to. Spectre effects all CPU vendors, while Meltdown is specific to Intel chips. More details below.Lucky for you, there are patches available to remediate or workaround the issue. The downside is there is up to a 30% performance reduction in CPU performance after installing these patches. Older intel CPU’s will be harder Read more […]


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How to Install Citrix Xenserver

This article is content I migrated from a previous site I had created. The information may be a bit out of dateIn this video I explain where to get Citrix Xenserver and how to install it. I use a Virtualbox Virtual Machine in my demonstration, however you would not want to run Xenserver in a Virtual Machine in your production environment. I can’t really think of a situation where you would want to do that.I hope you enjoy the video, and be sure to send me any questions you have either by commenting Read more […]


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Installing Virtual Box and Creating an Ubuntu virtual machine

This is content I migrated from a previous website, so some of the information is a little out of date. But the overall processes should still be the same. Virtual Box is a very simple virtual machine package which can be installed on Linux, Mac, Windows, and Solaris. It is open source, so you can compile it to run on other systems as well. In this tutorial video I will cover how to install virtual box and install your first virtual machine. The process of creating the virtual machine is does not Read more […]


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Automatically deploy Puppet agent on VMWare Templates

Ensuring your Puppet Agent is installed on all machines in your environment can be a challenging task.  Today I will share a tip on how you can ensure that the puppet agent us automatically deployed to all of your new virtual machines. Explanation When you deploy a VMWare template, you have the option to create a customization specification.  You can add a command to this customization specification to automatically deploy the puppet agent, after the template has finished deploying. One of Read more […]


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Virtual machine(s) invalid in vCenter

Sometimes virtual machines within your VMWare environment may show up as invalid. The machine is in-fact still running at this point; but you are unable to manage the virtual machine. This can happen for a few reasons, but in my experience the most common is when the esx host is unable to access the storage.

I have seen this caused by high latency when accessing an NFS datastore, when you leave an offline datastore mounted for an extended period, and I have also seen this happen when a SAN controller failover event occurs.

This condition happens when the esx host cannot access the vmx file (vmware configuration file) in the datastore, so VMWare just sort of forgets the configuration of the machine. The process which runs the virtual machine is still running on the host, so your VM does not crash. But, you still need to recover since HA, DRS, etc… no longer work when the VM is in this state.