Virtualization, Cloud, Infrastructure and all that stuff in-between

My ramblings on the stuff that holds it all together

Category Archives: Training

PowerCamp–weekend PowerShell Training Course

I came across this today on my Twitter feed, Thomas Lee is running a weekend course in PowerShell in London this April, the agenda is as follows..

What is A PowerShell PowerCamp?
This fast paced weekend event covers all the key aspects of Windows PowerShell – from the command line and writing production-oriented scripts. We start with the basics including installation and configuration, formatting and providers and remoting. We then look at scripting, managing script libraries using modules, using objects, and finishing with the PowerShell features added into Windows. We finish with a look at PowerShell in the cloud and what’s coming with PowerShell V3.

The PowerCamp event is all lecture plus Q&A, with the opportunity to type along with the tutor. There are no formal labs.

What is the Agenda?
Day 1 – The Basics
• PowerShell Fundamentals – starting with the key elements of PowerShell (Cmdlets, Objects and the Pipeline) plus installation, setup, and profiles
• Discovery – finding your way and learning how to discover more
• Formatting – how to format output nicely – both by default and using hash tables and display XML
• Remoting – working with remote systems using PowerShell’s remoting capabilities
• Providers – getting into OS data stores via PSProviders
Day 2 – Diving Deeper
• Scripting Concepts – automating everyday tasks including PowerShell’s language constructs, error handling and debugging (both from the command line and using an IDE)
• Modules – managing PowerShell script libraries in the enterprise
• .NET/WMI/COM Objects – working with native objects
• PowerShell and Windows Client/Server – how you can use built in PowerShell cmdlets
• PowerShell in Key Microsoft Servers – a look at PowerShell today in SQL, SCVMM plus a look forward to the future with SharePoint 2010
• PowerShell and the cloud – this module looks at PowerShell in the cloud and how you can use PowerShell to manage cloud computing.
• PowerShell V3 – this final module shows you what’s new in PowerShell V3.

I am planning to attend, the cost is £200; which is an absolute bargain IMHO, and especially so if (like me) you are a contractor and can do this over a weekend. I’ve attended a Microsoft deployment course taught my Thomas in the past and I can vouch that he’s an excellent instructor.

It looks like an excellent way for a relapsed coder like myself to get re-immersed, if you’re a frequent LonVMUG’er this is a good complement to Alan Renouf’s PowerCLI sessions.

For more info and the full agenda click here


8 Node ESXi Cluster running 60 Virtual Machines – all Running from a Single 500GBP Physical Server


I am currently presenting a follow-up to my previous vTARDIS session for the London VMware Users Group where I demonstrated a 2-node ESX cluster on cheap PC-grade hardware (ML-115g5).

The goal of this build is to create a system you can use for VCP and VCDX type study without spending thousands on normal production type hardware (see the slides at the end of this page for more info on why this is useful..) – Techhead and I have a series of joint postings in the pipeline about how to configure the environment and the best hardware to use.

As a bit of a tangent I have been seeing how complex an environment I can get out of a single server (which I have dubbed v.T.A.R.D.I.S: Nano Edition) using virtualized ESXi hosts, the goals were;

  • Distributed vSwitch and/or Cisco NX100V
  • Cluster with HA/DRS enabled
  • Large number of virtual machines
  • Single cheap server solution
  • No External hardware networking (all internal v/dvSwitch traffic)

The main stumbling block I ran into with the previous build was the performance of the SATA hard disks I was using, SCSI was out of my budget and SATA soon gets bogged down with concurrent requests which makes it slow; so I started to investigate solid state storage (previous posts here).

By keeping the virtual machine configurations light and using thin-provisioning I hoped to squeeze a lot of virtual machines into a single disk, previous findings seem to prove that cheap-er consumer grade SSD’s can support massive amount of IOps when compared to SATA (Eric Sloof has a similar post on this here)

So, I voted with my credit card and purchased one of these from Amazon – it wasn’t “cheap” at c.£200 but it will let me scale my environment bigger than I could previously manage which means less power, cost, CO2 and all the other usual arguments you try to convince yourself that a gadget is REQUIRED.

So the configuration I ended up with is as follows;

1 x HP ML115G5, 8Gb RAM, 144Gb SATA HDD c.£300 (see here) but with more RAM
1 x 128Gb Kingston 2.5” SSDNow V-Series SSD c£205

I installed ESX4U1 classic on the physical hardware then installed 8 x ESXi 4U1 instances as virtual machines inside that ESX installation


This diagram shows the physical server’s network configuration


In order for virtualized ESXi instances to talk to each other you need to update the security setting on the physical host’s vSwitch only as shown below;


This diagram shows the virtual network configuration within each virtualized ESXi VM with vSwitch and dvSwitch config side-side.


I then built a Windows 2008R2 Virtual Machine with vCenter 4 Update 1 as a virtual machine and added all the hosts to it to manage

I clustered all the virtual ESXi instances into a single DRS/HA cluster (turning off admission control as we will be heavily oversubscribing the resources of the cluster and this is just a lab/PoC setup


Cluster Summary – 8 x virtualized ESXi instances – note the heavy RAM oversubscription, this server only has 8Gb of physical RAM – the cluster thinks it has nearly 64Gb



I then built an OpenFiler Virtual Machine and hooked it up to the internal vSwitch so that the virtualized ESXi VMs can access it via iSCSI, it has a virtual disk installed on the SSD presenting a 30Gb VMFS volume over iSCSI to the virtual cluster nodes (and all the iSCSI traffic is essentially in-memory as there is no physical networking for it to traverse.


Each virtualized ESXi node then runs a number of nested virtual machines (VM’s running inside VMs)

In order to get Nested virtual machines to work; you need to enable this setting on each virtualized ESXi host (the nested VM’s themselves don’t need any special configuration)


Once this was done and all my ESXi nodes were running and settled down, I have a script to build out a whole bunch of nested virtual machines to execute on my 8-node cluster. the VM’s aren’t anything special – each has 512Mb allocated to it and won’t actually boot past the BIOS because my goal here is just to simulate a large number of virtual machines and their configuration within vCenter, rather than meet an actual workload – remember this is a single server configuration and you can’t override the laws of physics, there is only really 8Gb or RAM and 4 CPU cores available.

Each of the virtual machines was connected to a dvSwitch for VM traffic – which you can see here in action (the dvUplink is actually a virtual NIC on the ESXi host).



I power up the virtual machines in batches of 10 to avoid swamping the host, but the SSD is holding up very well against the I/O

With all 60 of the nested VMs and virtualized ESXi instances loaded these are the load stats










I left it to idle overnight and these are the performance charts for the physical host; the big spike @15:00 was the scripts running to deploy the 60 virtual machines


Disk Latency


Physical memory consumption – still a way to go to get it to 8Gb – who says oversubscription has no use? 🙂

image image

So, in conclusion – this shows that you can host a large number of virtual machines for a lab setup, this obviously isn’t of much use in a production environment because as soon as those 60VM’s actually start doing something they will consume real memory and CPU and you will run out of raw resources.

The key to making this usable is the solid state disk – in my previous experiments I found SATA disks just got soaked under load and caused things like access to the VMFS to fail (see this post for more details)

Whilst not a production solution, this sort of setup is ideal for VCP/VCDX study as it allows you to play with all the enterprise level features like dvSwitch and DRS/HA that really need more than just a couple of hosts and VMs to understand how they really work. for example; you can power-off one of the virtual ESXi nodes to simulate a host failure and invoke the HA response, similarly you can disconnect the virtual NIC from the ESXi VM to simulate the host isolation response.

Whilst this post has focused on non-production/lab scenarios it could be used to test VMware patch releases for production services if you are short on hardware and you can quite happily run Update manager in this solution.

If you run this lab at home it’s also very power-efficient and quiet, there are no external cables or switches other than a cross-over cable to a laptop to run the VI Client and administer it; you could comfortably have it in your house without it bothering anyone – and with an SSD there is no hard disk noise under load either 🙂

Thin-provisioning also makes good use of an SSD in this situation as this screenshot from a 30Gb virtual VMFS volume shows.


The only thing  you won’t be able to play around with seriously in this environment is the new VMware FT feature – it is possible to enable it using the information in this post and learn how to enable/disable but it won’t remain stable and the secondary VM will loose sync with the primary after a while as it doesn’t seem to work very well as a nested VM. If you need to use FT for now you’ll need at least 2 physical FT servers (as shown in the original vTARDIS demo)

If you are wondering how noisy it it at power-up/down TechHead has this video on YouTube showing the scary sounding start-up noise but how quiet it gets once the fan control kicks-in.

ML115 G5 Start-up Noise

Having completed my VCP4 and 3 I’m on the path to my VCDX and next up is the enterprise exam so this lab is going to be key to my study when the vSphere exams are released.

Misc bits of Useful, Recent VMWare News


I’ve been really busy the last couple of weeks and I’ve had to trim down my incoming RSS feeds, as there was too much noise and I was missing important things like the following;

  • Scott Lowe’s summary of sessions from VMWare’s partner Exchange, some useful information on Site Recovery Manger
  • The new VMWare Certified Design Expert (VCDX) certification – next step up from VCP, will have to have a look into it now I’ve finally managed to re-schedule my cancelled QA course – official VM announcement here.
  • Official Microsoft Clustering Support with ESX 3.5 Update 1 here
  • Some workarounds for deploying Windows Server 2008 with virtual center here – would have been nice if support was in an official update from VMWare soon; it’s not like it’s been beta’ing for a while is it (errr!)

VMWare Fast Track VCP Course – Lights Out Edition


I have been on a VMWare fast track course this week to complete my VCP cert; annoyingly the VCP is one of those vendor certifications where you need to prove you’ve sat the course as well as doing the exam to qualify as a “proper” VCP.

I’ve been doing it at QA-IQ in central London, and whilst I know most of the content its good for filling in the gaps and detail for the areas where my knowledge is high-level.

Unfortunately the building lost all power 1/2 way through yesterday and we had to finish the remaining theory for the day without PC’s or projectors etc. – full credit to the instructor who didn’t break a sweat doing so, I’d probably have sworn a lot more.

When I arrived this morning they still haven’t got power back on so the day has been cancelled, waiting for a call from our account manager to work out what to do next. it’s already a compressed version of 2 training courses and my schedule is pretty tight so wonder what’s going to happen.

EDF the electricity supplier are bringing in generators – so someone must have really broken it!