Hyper Converged

Hyper Converged infrastructure is based on servers where disks are Direct-Attached Storage (DAS) connected internally or by using a JBOD tray. Each server (at least four to implement Storage Space Direct) has their own storage devices. So there are no shared disks or JBODs.

Hyper Converged infrastructure is based on known features as Failover Cluster, Cluster Shared Volume, and Storage Space. However, because storage devices are not shared between each node, we need something more to create a Clustered Storage Space with DAS devices. This is called Storage Space Direct. Below you can find the Storage Spaces Direct stack.

On network side, Storage Space Direct leverage at least 10G networks RDMA capable. This is because replications that occur though Software Storage Bus need low latency that RDMA provides.

More on this link: https://technet.microsoft.com/en-us/windows-server-docs/storage/storage-spaces/storage-spaces-direct-overview?f=255&MSPPError=-2147217396

Nested Virtualized Windows Server 2016 Hyper-V Cluster LAB

Prior to deployment on production I wanted to test new Windows Server 2016 Hyper V Cluster. On paper it seems it didn’t change much from Windows Server 2012 R2 but still there is fear of unknown. My goal was to test all of it on my desktop workstation since it is quite good even after 3 years of service it is still capable of doing some serious business. Main new feature that will enable me to do this is called Nested Virtualization.

Well now after everything I must say I am impressed what I was capable to achieve and this will be series of articles and step by step instructions if you are interested in doing similar setup at your home or just part of it for fun.

First things comes first 🙂

In all possible scenarios planing and preparation is half work done right there, because of that we need detail plan of our future Hyper V cluster environment and all of it parts and envision our test case.

Windows Server 2016 Updates

Well after quite a few deployments of new Server I noticed that Windows update will throw warring and notification “Your device is scheduled to restart outside of active hours” even do you set it not to do so – it is set do DownloadOnly.

It seems that this is a known bug in the Windows Update Settings UI in which the text does not correctly reflect the configuration of your Windows Update settings. MS Server Team will make fix soon but for now if you don’t want your server to automatically restart this is what you need to check and configure :

Validate your current Update settings using SCONFIG

To determine what updates your machine has already installed, follow these steps:

  • Open a command prompt with Admin permissions.
  • Type sconfig and press Enter.
    • NOTE: There may be a short pause as the tool inspects your system.
  • Option #5 shows the current configuration of your Windows Update settings.

     

Add Nano Server to Domain

This is procedure how to add Nano Server to domain. Basic idea behind this is to do offline join to domain. Before you venture to adding Nano Server to domain you must set network address and adequate DNS record on your DNS server.

Nano server is a headless server which you cant RDP or not a command prompt. For Nano Server management we have to use PowerShell or RSAT tools. So as a first step is to login to other server which stays in the same network and run the PowerShell and execute the following commands.

First add the server to TrustedHost List

Set-Item WSMan:\localhost\Client\TrustedHosts "192.168.2.95" -Concatenate

Nano Server – Deployment

So, if you are an IT Pro you probably know that with Microsoft Server 2016 comes with something called Nano Server.

In my opinion it is the best of new thing that Server 2016 have. To see what is new in Windows Server 2016 check out this link on TechNet and if you have more time available there are a series of really good Microsoft Virtual Academy resources here.

Over the last few years the Microsoft tried to downsize their Windows Server product and answer on many issues that users had.

The first attempt to resolve these issues was in Server Core released as an installation option in Windows Server 2008. A command line only version of the Server OS that can be managed remotely and to a limited degree from a direct console This ‘server core’ did away with a lot of extraneous ‘stuff’ and meant fewer updates, smaller images and smaller, quicker installations.

But this was not enough and so the Server Product team in Microsoft went back to the drawing board and produced a deployment option now known as Nano server. This cannot be installed from the DVD or ISO, it has to be installed using PowerShell and each individual image built up to only contain the roles and services that are required for that particular server.

How to create a Hyper-V VM template

In this post I will look at creating a virtual machine (VM) template that you can use to quickly deploy new VM’s from, without having to install and patch them each time.

It is particularly useful if you are in a small Hyper-V environment and don’t have System Center Virtual Machine Manager (VMM).

The beauty of using a template for VM deployment is standardization. You deploy a known configuration which can be pre-patched which reduces time during the post deployment tasks.

Shared Nothing Live Migration

Shared Nothing Live Migration protects you from planned downtime (say you need to patch Windows on host or replace or upgrade some hardware components). See:

Shared Nothing Live Migration

For an unplanned downtime you need either VM HA (little downtime, little data loss, VM reboots) or guest VM cluster (no downtime, no data loss, VM turns to other host). See:

VMs for High Availability

Guest VM Cluster for HA

Run Hyper-V in a Virtual Machine with Nested Virtualization

Nested virtualization is a feature that allows you to run Hyper-V inside of a Hyper-V virtual machine. In other words, with nested virtualization, a Hyper-V host itself can be virtualized. Some use cases for nested virtualization would be to run a Hyper-V Container in a virtualized container host, set-up a Hyper-V lab in a virtualized environment, or to test multi-machine scenarios without the need for individual hardware. This document will detail software and hardware prerequisites, configuration steps, and limitations.

Prerequisites

  • A Hyper-V host running Windows Server 2016 or Windows 10 Anniversary Update.
  • A Hyper-V VM running Windows Server 2016 or Windows 10 Anniversary Update.
  • A Hyper-V VM with configuration version 8.0 or greater.
  • An Intel processor with VT-x and EPT technology.

Configure Nested Virtualization

  1. Create a virtual machine. See the prerequisites above for the required OS and VM versions.
  2. While the virtual machine is in the OFF state, run the following command on the physical Hyper-V host. This enables nested virtualization for the virtual machine.
Set-VMProcessor -VMName <VMName> -ExposeVirtualizationExtensions $true
  1. Start the virtual machine.
  2. Install Hyper-V within the virtual machine, just like you would for a physical server. For more information on installing Hyper-V see, Install Hyper-V.

Upgrade the virtual machine configuration version

Check the virtual machine configuration versions

  1. On the Windows desktop, click the Start button and type any part of the name Windows PowerShell.
  2. Right-click Windows PowerShell and select Run as Administrator.
  3. Use the Get-VM cmdlet. Run the following command to get the versions of your virtual machines.
    Get-VM * | Format-Table Name, Version

    You can also see the configuration version in Hyper-V Manager by selecting the virtual machine and looking at the Summary tab.

Upgrade the virtual machine configuration version

  1. Shut down the virtual machine in Hyper-V Manager.
  2. Select Action > Upgrade Configuration Version. If this option isn’t available for the virtual machine, then it’s already at the highest configuration version supported by the Hyper-V host.

Failover Cluster Quorum

This topic aims to explain the Quorum configuration in a Failover Clustering.

What’s a Failover Cluster Quorum

A Failover Cluster Quorum configuration specifies the number of failures that a cluster can support in order to keep working. Once the threshold limit is reached, the cluster stops working. The most common failures in a cluster are nodes that stop working or nodes that can’t communicate anymore.

Imagine that quorum doesn’t exist and you have two-nodes cluster. Now there is a network problem and the two nodes can’t communicate. If there is no Quorum, what prevents both nodes to operate independently and take disks ownership on each side? This situation is called Split-Brain. Quorum exists to avoid Split-Brain and prevents corruption on disks.

The Quorum is based on a voting algorithm. Each node in the cluster has a vote. The cluster keeps working while more than half of the voters are online. This is the quorum (or the majority of votes). When there are too many of failures and not enough online voters to constitute a quorum, the cluster stop working.

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