Benp's Guide to Stuff

Use PowerShell to Patch VHD and WIM Image Files

2010-11-15T14:42:28Z

Hi Everyone

I’ve written an article for the The Scripting Guy blog on how to use PowerShell to patch VHD and WIM image files.

Check it out!

http://blogs.technet.com/b/heyscriptingguy/archive/2010/11/14/use-powershell-to-patch-vhd-and-wim-image-files.aspx

Thanks

Ben

How To Figure Out Which Processes are Generating Disk IO in Windows 7

2010-08-19T11:41:04Z

This article is a step by step guide on how to identify how much data each process is writing to disk. It’s particularly relevant for VDI installations, but also applies to physical Windows 7 installations.

If you are using Windows 7 as a VDI client, you really care about disk IO. If you are using differencing disks you really care about disk writes.

More disk writes = (bigger child vhd * many virtual machines) = More Storage = More Dollars

Minimising the amount of data that is written to a disk can massively impact the scalability and performance of you solution. Before you can minimise it, you need to understand what is happening.

Installing the Tools

Install the Windows Performance Toolkit. To do this:

1. Install the Windows SDK

2. In BIN directory of the SDK install, locate the wpt_x64.exe or wpt_x86.exe file.

3. Copy the wpt_xXX.exe file to the machine to be monitored and install it.

4. In the install directory (normally C:\Program Files\Microsoft Windows Performance Toolkit) you should find XPerf.exe

Generate the Log File Using Xperf

1. Open a Command Prompt as administrator and navigate to the directory that contains Xperf.exe.

2. Start Kernel Tracing by running the command line.

xperf -on DiagEasy

3. Stop the tracing with this command line.

xperf -d c:\MyFolder\MyTrace.etl

Analysing the Trace in XPerf

These steps help you identify which processes are writing data

1. Open the Trace in XPef.

xperf c:\MyFolder\MyTrace.etl

2. Right Click on the “Disk” section of the graph click “Summary Table”.

3. Sort on “Write Size” to find the processes writing the most data and use “Path Name” to find the files being written to.

4. To get more details about each process, right click on the “Checkpoint” graph and select “Process Summary Table”.

5. Use the “Command Line” column to help identify how the process started. This is particularly useful for looking at what each svchost.exe is actually doing.

Analysing the trace in Excel

You might want to analyse the trace in a more familiar tool and generate some custom reports.

1. Open the Trace in XPef.

xperf c:\MyFolder\MyTrace.etl

2. Right click the “Disk” graph and select “Detail Graph”.

3. On the new graph right click and select “Summary Table”.

4. On the table right click, select “Export Full Table” and save to a CSV file.

5. Open the CSV file in Excel and save it as an Excel Workbook.

6. Insert a pivot table using the entire data set and set it up like this:

7. Filter the pivot table based on “Write” and the table should look like screenshot below. You might then want to sort the table on “Sum of IO Size”.

Next Steps

Note: “c:\Kernel.etl” is the file used to store all the performance data. This will grow to be quite large and can be discarded from your analysis as it is only generated when you are actively monitoring Windows.

By now you have a sorted list on which processes are writing the most data and to which files. You also have the exact command line that is calling each process. The next stage is the tricky part! You need to identify the purpose of the processes writing the data. Sadly, this stage is out of scope of this article. For this, the internet is your friend J

Hope this helps

BenP

Hyper-V Best Practice Analyzer - What does it check

2010-05-13T14:30:00Z

Hi All

Last month we released the Hyper-V Best Practice Analyser. I was interested to see what checks/rules the Best Practice Analyser made and used, so I started digging around. Because the Hyper-V Best Practice Analyser is based on the standard Best Practice Analyser technology provided in Windows 2008 R2, it was really easy to use PowerShell to find this information out.

Import-Module BestPractices

Get-BpaModel

Get-BpaResult Microsoft/Windows/Hyper-V

Get-BpaResult Microsoft/Windows/Hyper-V | ft title

SIMPLES!!

Below is a list of the 29 rules that were listed:

1. The Hyper-V Virtual Machine Management Service should be configured to start automatically

2. The Hyper-V Networking Management Service should be configured to start automatically

3. The Hyper-V Image Management Service should be configured to start automatically

4. Hyper-V should be the only enabled role

5. The Server Core installation option is recommended for servers running Hyper-V

6. Domain membership is recommended for servers running Hyper-V

7. The number of logical processors in use must not exceed the supported maximum

8. The number of virtual processors in use must not exceed the supported maximum

9. More than one network adapter should be available

10. Reserve one or more external virtual networks for exclusive use by virtual machines

11. All virtual network adapters should be enabled

12. The number of virtual machines must be within supported limits

13. Use RAM that provides error correction

14. Configure the server with a sufficient amount of dynamic MAC addresses

15. Avoid pausing a virtual machine

16. Offer all available integration services to virtual machines

17. Enable all virtual network adapters configured for a virtual machine

18. Storage controllers should be enabled in virtual machines to provide access to attached storage

19. Display adapters should be enabled in virtual machines to provide video capabilities

20. Run the current version of integration services in all guest operating systems

21. Enable all integration services in virtual machines

22. Avoid using legacy network adapters when the guest operating system supports network adapters

23. Avoid using snapshots on a virtual machine that runs a server workload in a production environment

24. Dynamic virtual hard disks are not recommended for virtual machines that run server workloads in a production environment.

25. Avoid using differencing disks on virtual machines that run server workloads in a production environment

26. Configure a virtual machine with a SCSI controller to be able to hot plug and hot unplug storage

27. Configure SCSI controllers only when supported by the guest operating system

28. Avoid configuring virtual machines to allow unfiltered SCSI commands

29. Windows Server 2008 R2 should be configured with the recommended amount of memory

Hope this helps!

Benp

PowerShell Resources

2009-12-02T11:53:00Z

Hi All

I`m regularly asked what resources I would recommend to people who want to develop their PowerShell scripting skills. So I’ve worked with some of my colleagues to create a list of resources that we regularly point people to. There are absolutely loads of resources that are not listed here, but these are some of the good ones that we know about. I`ll try and update this list dynamically as time goes on.

Microsoft Windows PowerShell Links

Scripting with Windows PowerShell Homepage

Windows PowerShell Owner’s Manual

Windows PowerShell Cmdlets

VBScript To Windows PowerShell Conversion Guide

Windows PowerShell Getting Started Guide

Windows PowerShell About Help Topics

Windows PowerShell Cmdlet Help Topics

Windows PowerShell Provider Help Topics

Windows PowerShell ISE Help

Windows PowerShell 2.0 Glossary

Windows PowerShell Quick Reference

Computer Performance

WMI Win32 Reference

PowerShell Cheat Sheet

Blogs

Hey Scripting Guy

Windows PowerShell Blog

Richard Macdonald Blog

The PowerShell Guy

Richard Siddaway Blog

BenP Blog

Active Directory

WMI Blog

Script Libraries

Windows PowerShell Script Repository

Codeplex

PowerShell.com

PowerShellCommunity.Org

poshcode.org

Modules and Tools

PowerGui

Hyper-V Library

AD Cheat Sheet

Webcasts

One Cmdlet, Two Cmdlet, Three Cmdlet, Four: An Introduction to Windows PowerShell Commands (Level 200)

Object, Objects Everywhere: Working with Objects in Windows PowerShell (Level 200)

New Kid on the Scriptblock: Writing Scripts with Windows PowerShell (Level 200)

Amazing but True: Things You Never Dreamed You Could Do with Windows PowerShell (Level 200)

Managing Large Infrastructures with Windows PowerShell 2

Windows, PowerShell and WMI, Unveiling Microsoft’s Best Kept Secret

Books

Windows PowerShell in Action

Windows PowerShell CookBook

Windows PowerShell Step By Step

Windows PowerShell 2.0 Administrator's Pocket Consultant

Thanks

BenP

Managing Large Infrastructures with PowerShell v2

2009-01-06T13:32:00Z

Hi All

I had the pleasure of speaking at Tech Ed EMEA this year on the subject "Managing Large Infrastructures with PowerShell v2". I co-presented the session with Jeffrey Snover and a recording of this session has been uploaded to the microsoft site. Here it is:

http://www.microsoft.com/emea/teched2008/itpro/tv/default.aspx?vid=80

Cheers

BenP

Interview with me on the Get-Scripting Blog

2009-01-06T13:10:00Z

Hi All

I met Jonathan Medd at Tech Ed EMEA this year and he kindly invited me to be interviewed for his PowerShell podcast. If you would like to listen to the podcast it's here:

http://get-scripting.blogspot.com/2008/12/get-scripting-podcast-episode-6-ben.html

Happy New Year

BenP

Scripting Hyper-V with WMI and PowerShell: Part 1 – Introduction + Querying State

2008-08-11T18:37:00Z

Scripting Hyper-V with WMI and PowerShell

Part 1 – Introduction + Querying State

Introduction

When it comes to scripting Hyper-V there are really 2 methods:

1. Using the virtualization WMI provider that ships with Hyper-V.

2. Using the cmdlets provided by System Centre Virtual Machine Manager 2008

So which option should you use? Well if you want an easy life, the answer is absolutely Option 2. Use SCVMM 2008, and scripting Hyper-V is like a pleasurable dream. The cmdlets are task orientated, provide a rich set of features and really do work very well. So why is this a guide to Option 1 – Using the virtualization WMI provider? Well, sometimes Hyper-V will be used without an accompanying System Centre deployment, and if that’s the case, using WMI is your only scripting option.

I`ll be honest, using the WMI provider to script Hyper-V is unintuitive, complicated and feels quite clunky. So the question has to be asked “Why is the Hyper-V WMI provider so difficult to use?” The answer is Industry Standards. The virtualization WMI provider fully complies with the standards outlined by the Distributed Management Task Force (DMTF). Whilst standards are great for creating consistency among different vendors, there are often comprises with the simplicity of individual solutions. Contrastingly the SCVMM cmdlets are a bespoke solution designed by Microsoft to be simple, intuitive and powerful, but do not adhere to any industry standards.

So, with the expectation that the Hyper-V WMI journey will be a challenging one, let’s get on with it.

WMI Basics

As mentioned we will be using the virtualization WMI provider, and before going any further I would strongly recommend that you spend some time understanding WMI to a reasonable depth. If you can answer the following questions, you’re probably familiar enough with WMI to get the most out of this tutorial:

1. What is namespace?

2. What is a class?

3. How do you create a WMI Object in PowerShell?

Basic WMI information is out of scope for this tutorial, so if you can’t answer the above questions, before continuing I would suggest the following pre-reading/viewing:

1. Brief WMI Intro on Technet Edge - http://edge.technet.com/Media/Powershell-tips-and-tricks-from-the-field-with-Ben-Pearce

2. Windows, PowerShell and WMI – Tech Ed 2008 Session http://www.microsoft.com/emea/spotlight/sessionh.aspx?videoid=996

3. Microsoft Windows PowerShell Step by Step Book- http://www.microsoft.com/MSPress/books/10329.aspx

Hyper-V + WMI

There are 2 key points you need to understand to start using the Hyper-V WMI provider.

1. All Hyper-V classes live in the “Virtualization” namespace. Therefore whenever you want to instantiate an object you need to specify this namespace. The following sample lists all the classes available in this namespace:

Get-WMIObject –namespace “root\virtualization” -list

2. PowerShell must be elevated and running as an administrator. If you run PowerShell in a non-administrative context you will not be able to connect to any guests, and will only be able to affect the host. In Server 2008 you need to right-click the PowerShell icon, then click “Run As Administrator” to achieve this, even if logged on as an administrator.

VMStateQuery

Often, I find the best way to learn something is with a worked example. Attached to this post is VMStateQuery.ps1, which is an example PowerShell script which can be used to determine the state of guests deployed to a Hyper-V host. The script can be used to return the state of all guests on a host, or the state of 1 particular guest.

Usage

.\VMStateQuery.ps1

This returns a list of all guests and their state, sorted alphabetically.

.\VMStateQuery.ps1 -vhost myremotehost -sortbystate

This returns a list of all the guests on MyRemoteHost, and sorts the guests by state.

.\VMStateQuery.ps1 –vhost myremotehost –vguest MyGuest1

This returns the state of the guest MyGuest1, running on the host MyRemoteHost.

Explanation

Let’s dig into some interesting parts of this script.

The only time we use WMI in this example is in this 1 line:

$vms = Get-WMIObject -Class Msvm_ComputerSystem -Namespace "root\virtualization" -ComputerName $vhost

This line connects using WMI and retrieves all instances of MSVM_ComputerSystem on the computer specified by $VHost. This line returns an array of all guests and the host, each one represented by an object. In order to find out what we can with this object type we can do two things. Firstly, use Get-Member to obtain all properties and methods, or use this MSDN link, which details each property and method.

Having looked at the properties of this object we can see 2 properties that will be particularly useful when trying to query a guest’s state: elementname and enabledstate. ElementName is the name of the guest that you see in the Hyper-V MMC console, and enabledstate is a number that represents the state of the machine.

This bit of code filters our array of guests, and returns any that match the following

$vms = $vms | where-object {$_.elementname -eq $vguest}

We simply use where-object to filter, such that only guests whose elementname equals $vguest are retained.

We use the enabledstate property to identify the state of the machine. However, the state of the machine is a number which might not make too much sense. Therefore I’ve created a function called ConvertStateToFriendly which simply uses a switch statement to return a friendly word for the state. The call to this function is nested as an expression that can be used by the format-table cmdlet to display the information nicely. Here’s the code:

$statefriendly = @{Expression={convertStateToFriendly $_.enabledstate};Label="State";width=25}

$vms | format-table Elementname, $statefriendly

This code looks a little bid nasty, but is simply a way of creating custom tables. More details on how this mechanism works can be found here.

One final part I want to explain is this line:

$vms = $vms | where-object{$_.caption -ne "Hosting Computer System"}

When you get all instances of MSVM_ComputerSystem, one of the returned objects represents the host system. In this script I am not really interested in the state of the host, just the state of the guests. Therefore the above line simply looks at the caption property of the objects, and drops the object with the name “Hosting Computer System”.

All the rest of the script is generic PowerShell code, used for parameters, error checking and other useful bits and pieces.

Hyper-V WMI Resources

The two best resources for Hyper-V WMI scripting that I have come across so far are the MSDN page, and James O’Neil’s Hyper-V management library on CodePlex. The MSDN page is the definitive source on the WMI provider and is here:

http://msdn.microsoft.com/en-us/library/cc136992(VS.85).aspx

The Code Plex project which James uploaded is a pretty comprehensive library on managing Hyper-V and WMI. It’s an excellent source, but be warned it is pretty hardcore and very code efficient in places, which can sometimes be quite tricky to understand (maybe that’s just me J)

http://www.codeplex.com/PSHyperv

My colleague Richard Macdonald has written a very similar script, but using C# instead of PowerShell. Check out his blog here for the code.

Well that’s it for part 1. Stay tuned for Part 2 –Hyper-V Data Gathering.

Enjoy

BenP

Inteverview with me on Technet Edge

2008-06-23T22:01:00Z

Hi All

I got kidnapped by the Tech Net Edge guys whilst I was at Tech Ed the other week, and intereviewed about the PowerShell and WMI session that I was presenting there. If you'd like to see the interview in full it's here:

http://edge.technet.com/Media/Powershell-tips-and-tricks-from-the-field-with-Ben-Pearce/

You might need to use "the force" whilst watching the demos, as sadly some of the commands I was using were slightly off the screen.

Have fun

BenP

How to Configure a Server Core Domain Controller: Vanilla to First DC in a Forest

2008-06-20T10:43:00Z

Hi All

Sometimes you just want a new Domain created quickly for a bit of testing. Given that Windows 2008 ships with server core, a light footprint version of the OS, it’s ideal for being the domain controller. As I am fairly inexperienced with Server Core I had to search all over the place to find information on how to go from a vanilla server core build, to a dc running a brand new domain. I figured out a set of commands that achieve this, so thought I would share them with the world.

Rename Host

Netdom renamecomputer <OldName> /NewName:<NewName>

Set IP

netsh int ip set address "Local Area Connection" static 192.168.0.210 255.255.255.0 192.168.0.1 1

Set DNS

Netsh interface ipv4 add dnsserver name=”<idxname>” address=<IP Address> index = 1

Install DNS Role

start /w ocsetup DNS-Server-Core-Role

Create New Domain

dcpromo /unattend:c:\unattend.txt

Unattend.txt Contents

[DCINSTALL]
AutoConfigDNS=Yes
DomainNetBiosName=benpdom
NewDomainDNSName=benpdom.com
ReplicaOrNewDomain=Domain
NewDomain=Forest
ForestLevel=3
DomainLevel=3
SafeModeAdminPassword=Password1234
RebootOnSuccess=Yes

Another cool Server Core reference can be found on Mark’s blog here:

http://blogs.technet.com/mempson/archive/2008/03/19/server-core-quick-reference-guide.aspx

Hope this helps

Cheers

BenP

Tech Ed 2008 - Demo 5 - Administering Failover Clustering

2008-06-12T21:02:00Z

Finally, here is the last demo.

Demo 5 – Administering Failover Clustering

I have already written a detailed post, and a similar script on this subject, here. However, I promised all the demos would be on my blog, so attached is the exact script I used at Tech Ed 2008.

Enjoy!

BenP