The First 2012 R2 Doc – Test Lab Guide For System Center 2012 R2 & WS2012 R2 Hyper-V Network Virtualization

*sniff sniff*  It’s that time in the schedule when documentation starts to appear right before a scheduled Microsoft release, this time it’s the preview of Windows Server 2012 R2 and System Center 2012 R2 (WSSC 2012 R2).

Microsoft has released a step-by-step guide for building a test lab to help you learn & evaluate Hyper-V Network Virtualization (HNV aka software defined networking aka SDN), using:

  • Windows Server 2012 R2
  • Windows Server 2012 Hyper-V
  • System Center 2012 R2 – Virtual Machine Manager

This document contains instructions for setting up the Windows Server® 2012 R2 Hyper-V Network Virtualization with System Center 2012 R2 VMM test lab by deploying four physical server computers running Windows Server 2012 R2 and ten virtual machines running Windows Server 2012 R2. The resulting configuration simulates two customer private intranets, one simulated hoster datacenter environment, and the Internet.

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The lab requires 4 physical servers:

  • WNVHOST1: Running Windows Server 2012 R2 Hyper-V, DC, and DNS
  • WNVHOST2: WS2012 R2 Hyper-V host, SQL server, IPAM server, and System Center 2012 R2 Virtual Machine Manager.  Some tenant VMs (simulated on-premise) are also running here.
  • WNVHOST3: Another WS2012 R2 host, but this is going to run the VM running the new WS2012 R2 HNV Gateway role, integrating the on-premise networks with the hosted VM Networks.
  • WNVHOST4: Another host running a bunch of “hosted” tenant VMs in isolated VM Networks.

The doc goes step-by-step through building the lab.  Bet you can’t wait to get your hands on WSSC 2012 R2 now Smile

KB2858695 – Unable To Use kdump or kexec On Linux VMs On Hyper-V

Microsoft has released a knowledge base article to deal with a situation where you are unable to use kdump or kexec for Linux virtual machines on Hyper-V.

Symptoms

Consider the following scenario:

  • You have a computer that is running a Microsoft Windows operating system with the Hyper-V role installed.
  • You install Linux in a Hyper-V virtual machine on the computer.
  • You configure kdump on Linux VM which already has the Linux Integration Services drivers either pre-built or manually installed.

In this scenario, if the Linux virtual machine crashes, the core dump of the Linux kernel is not generated.

Cause

This issue occurs because Hyper-V is unable to host two simultaneous connections from the same synthetic driver running inside a virtual machine.

When kdump is configured on a Linux virtual machine that is using the Linux Integration Services synthetic storage driver (also known as storvsc), the kexec kernel is configured to use the same driver. If the Linux virtual machine crashes, the synthetic storage driver hosted in kexec kernel attempts to open up a connection to the Hyper-V storage provider. However, Hyper-V fails to establish the new connection because of the pre-existing connection to the same storage driver within the crashed Linux virtual machine. Due to this reason, the kexec kernel is unable to dump core for the crashed Linux virtual machine.

Resolution

To resolve this issue, configure the kexec kernel with the standard Linux storage driver. This configuration needs to be done after the kdump functionality is enabled on a Linux virtual machine. The basic idea is to turn off the Linux Integration Services storage driver and then enable the standard Linux storage driver inside the kexec kernel by using the prefer_ms_hyper_v parameter at strategic locations.

There are more instructions on the KB article to deal with resolving this issue with each of the supported distros.

No Need To Wait For XboxOnePointOne

I recently asked if Microsoft was pulling a “Windows 8” with the new Xbox One, with them apparently once again stubbornly making very unpopular decisions, this time restricting usage of the new console that was damaging sales and market share.  The mass media and users in general spoke, and it was not pretty.  For example, I heard yesterday (second hand) that a local store was pre-selling 45:1 PS4:Xbox One.

Instead of waiting for vNext of Xbox (which would have been really bad, like Windows Phone 3% market share bad) Microsoft made some policy changes before the Xbox One release, as Paul Thurrot reported.

While a vocal minority are unhappy with the 180 degree course change on these policies, that vast majority (including me) are happy.  Now I would also like to see the price come down by €100 by unbundling the Kinect because I am sure that will be a factor when people buy these devices – not everyone is a hardcore gamer that’ll pay no matter what, and few people have room to even use a Kinect (we don’t all live in Redmond-sized mansions). 

Is the policy change too late?  Is the damage already done?  Every mass media outlet has already declared the PS4 as the winner when the scandal broke.  Only some of the tech press covered the policy changes that were announced yesterday.  Xbox One is set in the minds of the general, non-tech-media-reading consumer as the inflexible, locked-down, and consumer-unfriendly media-playing-first & games-second console (which is 5 times more expensive than a Roku media player and does little more than a smart TV in the media context).  I think Microsoft are going to have to spend a lot of money to recover from the awful original policy decisions.  And someone’s head needs to roll for this.

What sort of vacuum were the Xbox group in when they thought that always-on for daily activation and restricted games trading would be OK with the market?  Who didn’t give negative feedback internally?  Who was the yes man?  Who was deaf to criticism?  Was this a symptom of the “always be positive” culture that infects parts of MSFT even when the car is racing towards the cliff?  Some folks in MSFT hate what they see as negativity and want everyone to be rah-rah-rah with the impending doom no matter what, thinking that cheerleading will turn things around.

The policy changes are now enough for me keep my Xbox One pre-order, I think.  I’m actually not sure.  I have a funny feeling that I’ll continue to spend more time on my Xbox 360 thanks to GTAV and I will continue to use my reliable and simple Roku as the media device (Xbox Live is almost worthless outside of the USA for online media and ropey as a file player).  Maybe I will cancel the pre-order and wait for the inevitable post-Christmas price cuts and for games I actually want to appear.

Windows Server 2012 R2 Hyper-V – Linux Support Improvements

Yes, Hyper-V supports many Linux distros, architectures, and versions, and that support has been improved in WS2012 R2 Hyper-V.

It’s no secret that there were some changes to the Linux Integration Services that are built into the Linux kernel.  Those changes were intended for and supported on WS2012 R2 Hyper-V (not WS2012 Hyper-V).  Those two changes are:

  • Dynamic Memory: Linux guest OSs can use the balloon driver to have the exact same support for Dynamic Memory as Windows (add and remove).  Bear in mind the constraints of the Linux distro itself.  And remember the recommendations of Linux when assigning large amounts of CPU/RAM to a machine.  These are Linux recommendations/limits, not Hyper-V ones.
  • Online backup: You can now perform a file system freeze in the Linux guest OS to get a file system consistent backup of a Linux guest OS without pausing the VM.  Linux does not have VSS (like Windows) so we cannot get application consistency.  But this is still a huge step forward.  According to Microsoft, WS2012 R2 Hyper-V is now the best way to virtualize and backup Linux; you can use any backup tool that supports Hyper-V to reliably backup your Linux VMs without using some script that does a dumb file copy.

Remember that online VHDX resizing is a host function, so Linux guest OSs support this too.  Don’t ask me how to resize Linux partitions or make use of the new free space Smile

There is also a new video driver for Linux.  This gives you a better video experience as with the Windows guest OS, including better mouse support – but hey, real Linux admins don’t click!

To take advantage of these features, make sure you have an up-to-date Linux kernel in your VMs, and your running them on WS2012 R2 Hyper-V.

PowerPoint – E2EVC Copenhagen Microsoft Virtualisation Keynote

I recently did a presentation called “What’s New In Microsoft Virtualization” at the E2EVC event in Copenhagen, Denmark.  It was a 45 minute slot and there was so much to cover.  So I had to be picky about what I presented on.  This is the deck that I used:

 

PowerPoint – Why Upgrade To Windows Server 2012

A few months ago myself and Dave Northey (then a DPE with MSFT Ireland) did a road show around Ireland discussing the reasons that companies should upgrade to Windows Server 2012.  We deliberately excluded discussions of Hyper-V … mainly cos I’ve been beating people around the head on that topic Smile  Here’s the deck we presented:

 

Windows Server 2012 R2 Hyper-V – Live Virtual Machine Export/Clone

This is a feature that DevOps, administrators, app-owners, and testers are going to like.  You can clone a running virtual machine!  This will produce an exact copy of the running virtual machine without a sysprep.  You can then power up this virtual machine on an isolated virtual switch or VM Network, connect to it via the new Remote Desktop enabled Connect, and do whatever you need to do:

  • Test an OS upgrade
  • Test an app upgrade
  • Test patches or hotfixes
  • Test backup/restore
  • Troubleshoot an OS or service
  • Troubleshoot an issue

And you can do all that without affecting production systems because you’re doing it with an exact clone of the production VM(s).  This is great because you don’t need to delay doing diagnostics.  You can figure out the fix, and then implement the fix really quickly to the production system.  Those for you with change control will have had the opportunity to test those upgrades/fixes and the rollback plan too.

A very cool sub-feature of live cloning/export is that you can export a snapshot of a virtual machine.  Get your head around that!  It exports a clone of the VM as it was when the snapshot was created.

When you create a clone of a running VM, the wizard allows you to configure what to do with the resulting VM so that you can keep that identical IP address, computer name, and SID on a different virtual switch/VM Network.  If you clone to a VMM library then the resulting VM is in a saved state. If you clone to another computer then it will be auto-started.  The wizard allows you to select a different network to avoid conflicts … so be careful.

Upgrading From Windows Server 2012 Hyper-V To Windows Server 2012 R2 Hyper-V

This post is being written before the preview release is out, and before guidance has been written. It is based on what we know from TechEd NA 2013.

Upgrading a non-clustered Hyper-V host has never been easier.  Microsoft did some work to increase compatibility of VM states between WS2012 and WS2012 R2.  That means you don’t need to delete snapshots.  You don’t need to power up VMs that were in saved states and shut them down.  Those files are compatible with WS2012 R2 Hyper-V.

There are 2 ways to upgrade a WS2012 R2 Hyper-V host.

Do An In-Place Upgrade

You log into your WS2012 R2 host, shutdown your VMs or put them in a saved state, pop in the WS2012 R2 media, and do the upgrade.  The benefit is that you retain all your settings, and the VMs are right there in Hyper-V Manager with no effort.  The downside is that any crap you might have had on the Management OS is retained.  Microsoft always recommends a fresh install over an in-place upgrade.

Replace The Management OS & Import/Register The VMs

I prefer this one.  But be careful – do not use this approach if any of your VM files/settings are on the C: drive of the host – I hate those default locations in Hyper-V host settings.

You shutdown the host, pop in the media, and do a fresh install over the C: drive of the host.  This gives you a completely fresh install.  Yes, you have to rebuild your settings but that can all be scripted if you’re doing this a lot.  The final step is to import the VMs using the register option.  This simply loads up the VMs, and then you start up whatever VMs you require.

Upgrading to Windows 8.1 Client Hyper-V

This is a little off-topic but it’s related.  You can upgrade a PC from Windows 8 with Client Hyper-V to Windows 8.1.  The upgrade will automatically put running VMs into a saved state.  After the upgrade, the previously running VMs will be running.

Integration Components

The final step in any Hyper-V upgrade is to upgrade the Hyper-V Integration Components in the guest OS of each virtual machine.

Windows Server 2012 R2 Hyper-V – Online Resizing of VHDX

The most common excuse given for using pass-through disks instead of VHDX files was “I want to be able to change the size of my disks without shutting down my VMs”.  OK, WS2012 R2 Hyper-V fixes that by adding hot-resizing of VHDX files.

Yes, on WS2012 R2 Hyper-V, you can resize a VHDX file that is attached to a VM’s SCSI controller without shutting down the VM.  There’s yet another reason to place data in dedicated VHDX files on the SCSI controller.

You can:

  • Expand a VHDX – you’ll need to expand the partition in Disk Manager (or PoSH) in the VM – maybe there’s an Orchestrator runbook possibility
  • Shrink a VHDX – the VHDX must has un-partitioned space to be shrunk

This resize is a function of the host and has no integration component dependencies.

That’s one more objection to eliminating the use of pass-through disks eliminated.

Windows Server 2012 R2 Hyper-V – Live Migration Improvements (Compression and SMB 3.0)

Live Migration is pretty quick in WS2012 Hyper-V, with support for huge bandwidth with no arbitrary hard limit on the number of concurrent Live Migrations.  With the potential for huge hosts (4 TB RAM) and huge VMs (1 TB), Microsoft wanted to make it quicker to move VMs, vacate hosts, and to do general maintenance, such as Cluster Aware Updating.  That’s why they added support for faster Live Migration using SMB 3.0 and compression in WS2012 R2 Hyper-V.

Out of the box, WS2012 R2 Hyper-V is able to compress Live Migration traffic.  It does this by taking any free CPU resources that are available on the host – typically CPU is underutilized on hosts.  Hyper-V will prioritize other tasks when scheduling the processor.  That means if a VM needs more CPU, then Live Migration compression will get less processor access and not impact production systems.  Compression is enabled by default and does not require any special hardware.  It is expected that Live Migration compression will halve the time it takes to move a VM.

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If you have access to high end networking then you will want to enable Live Migration over SMB.  This will leverage the improvements in SMB from WS2012:

  • SMB Multichannel: Live Migration will be able to use more than one NIC which means it can get more overall bandwidth.  SMB Multichannel automatically discovers new NICs between the SMB client and server and automatically deals with NIC/path failure.
  • SMB Direct: This is where you have an RDMA enabled NIC/network, such as iWARP (10 Gbps), ROCE (10/40 Gbps), or Infiniband (56 Gbps).  The flow of traffic is faster (less latency) and has less impact on the CPU of the SMB client and server.

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On servers with PCI3 slots, 3 of these NICs can give you Live Migration speeds where RAM access speeds become the bottleneck Open-mouthed smile

There are 3 scenarios I can think of now, and here are the recommendations from Microsoft for them:

10 GbE or Slower NIC for Live Migration

Use the default compressed Live Migration.  This applies even if you have lots of 1 GbE NICs – compression will be more effective than SMB 3.0 at these speeds.

2 or More 10 GbE NICs for Live Migration

Use SMB Live Migration.  This will leverage SMB Multichannel to span all of the Live Migration NICs.  But watch that CPU utilization on the host.  And that leads us to …

1 or More RDMA NICs for Live Migration

Use SMB Live Migration.  This will leverage SMB Direct for really fast Live Migration with low CPU utilization (RDMA offloads processing to the NIC).  And if you have more than one NIC you get the best of both worlds by also leveraging SMB Multichannel.

Long story short: Live Migration will be very fast on WS2012 R2 Hyper-V, and you’ll see those improvements even on typical 1 GbE networking.