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On Windows PowerShell and other admin-related topics

How to configure AntiAffinityClassNames in Failover Clustering using Windows PowerShell

AntiAffinityClassNames is a cluster group property in Windows Failover Clustering used to identify cluster groups that should not be hosted on the same node. When working with clustered Hyper-V environments there is a 1:1 relationship between a cluster group and a virtual machine, and thus we can configure Anti-Affinity for virtual machines using the AntiAffinityClassNames property. For more information, see the links in the resource section in the bottom of the article.

What I want to show in this article is how to configure the AntiAffinityClassNames property using PowerShell. Most articles I have seen in regards to AntiAffinityClassNames covers how to use cluster.exe to configure the property, and since the cluster.exe was deprecated in Windows Server 2008 R2 (it`s still available as a deprecated command) it might be a good idea to learn how to configure this using the new Failover Clustering PowerShell module. In addition you also get other benefits available in PowerShell such as pipelining, export/import to/from different data sources, grouping and so on.

AntiAffinityClassNames is a property of a cluster group, but before we configure the property we need to look at what type it is. We can do this by piping the output of Get-ClusterGroup to the Get-Member cmdlet:

image

We can see in the definition of the property that it is a System.Collections.Specialized.StringCollection type. This means we can not just pass a text string as the property value, we need to create a object of the correct type. The reason this property is not just a System.String (text string) is that a Cluster Group can have more than one AntiAffinityClassNames values. System.Collections.Specialized.StringCollection has a method called Add which can be used to to add values to the collection. Here is a complete example on how to create such an object, add a couple of values to it and at the end assign it to the AntiAffinityClassNames property of a cluster group:

$value = New-Object System.Collections.Specialized.StringCollection
$value.Add("Domain Controllers")
$value.Add("Infrastructure Server Group")
(Get-ClusterGroup "SCVMM SRV01 Resources").AntiAffinityClassNames = $value

Note that this will overwrite any existing values. As we can see it is not very hard to configure a new value, but it might be harder if you want to preserve existing values remove single items of the existing value and so on. In order to make this easier I have created a PowerShell module which contains 3 script cmdlets for managing AntiAffinityClassNames:

image

As you can see in the cmdlet help there is support for pipeline input, which makes it possible to configure the AntiAffinityClassNames values based on input such as a CSV-file:

image

I have also provided examples for the script cmdlets:

image

 

Installing the AntiAffinityClassNames module

Download and unzip AntiAffinityClassNames.zip in the following location: %userprofile%\Documents\WindowsPowerShell\Modules\AntiAffinityClassNames

Alternatively you may save the module in any of the folders in the $Env:PSMODULEPATH variable or import the module from a custom path (Import-Module <path>\AntiAffinityClassNames). Here is some more examples to get you started:

# Import the module
Import-Module AntiAffinityClassNames

# Example usage of the Get-AntiAffinityClassNames script cmdlet

Get-AntiAffinityClassNames -Cluster cluster01.domain.local

Get-AntiAffinityClassNames -Cluster cluster01.domain.local -ClusterGroup "SC VMM SRV01 Resources"

Get-AntiAffinityClassNames -Cluster cluster01.domain.local | Export-Csv -Path c:\temp\AntiAffinityClassNames_cluster01.csv -NoTypeInformation

# Example usage of the Set-AntiAffinityClassNames script cmdlet

Set-AntiAffinityClassNames -Cluster cluster01.domain.local -ClusterGroup "SC VMM SRV01 Resources" -Value "Domain Controllers"

Set-AntiAffinityClassNames -Cluster cluster01.domain.local -ClusterGroup "SC VMM SRV01 Resources" -Value "Domain Controllers" -Keep

Set-AntiAffinityClassNames -Cluster cluster01.domain.local -ClusterGroup "SC VMM SRV01 Resources" -Value "Domain Controllers" -Verbose

# Example usage of the Remove-AntiAffinityClassNames script cmdlet

Remove-AntiAffinityClassNames -Cluster cluster01.domain.local -ClusterGroup "SC VMM SRV01 Resources" -Clear

Remove-AntiAffinityClassNames -Cluster cluster01.domain.local -ClusterGroup "SC VMM SRV01 Resources" -Value "Domain Controllers"

Remove-AntiAffinityClassNames -Cluster cluster01.domain.local -ClusterGroup "SC VMM SRV01 Resources" -Value "Domain Controllers" -Verbose

 

Resources

MSDN: AntiAffinityClassNames

Failover behavior on clusters of three or more nodes

Understanding Hyper-V Virtual Machine (VM) Failover Policies

Private Cloud: Configuring anti-affinity between VMs on Hyper-V 2008 R2 SP1 and VMM 2012

How to automatically avoid running Exchange VMs on the same Hyper-V server after a host failure

Get started with the Failover Clustering PowerShell-module

Enable Persistent Mode for Cluster Resource Groups using the PowerShell Failover Clustering module

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February 23, 2012 Posted by | Failover Clustering, Hyper-V R2, Virtualization, Windows PowerShell, Windows Server 2008 R2 | , | Leave a comment

Demos, slides and videos from Nordic Infrastructure Conference 2012 sessions

On January 13th – 14th the Nordic Infrastructure Conference (NIC) was arranged in Oslo, Norway for the first time. The goal for the conference is creating a premier event for all IT-professionals in the Nordics, and the first edition of NIC was a great success with a number of excellent speakers.

 

Demos, slides and videos from my 3 sessions at the NIC conference is now available:

Session

Description

Slides

Demos

Video

Introducing PowerShell 3.0

Since Windows 7 and Windows Server 2008 R2, Windows PowerShell has been a part of the core operating system, meaning we will see the next version of PowerShell in Windows 8. In this session we will look at what`s new in Windows PowerShell 3.0, based on the Windows Developer Preview released at the BUILD conference in September. You will get to see new features in PowerShell itself, as well as new modules for managing Windows 8 and Windows Server 8.

Link

Link

Link

Practical PowerShell for the Windows Administrator

Have you ever needed to perform the same task on more than one server? In this session you will see demos on how you can manage Windows systems using Windows PowerShell. You will get to see different techniques for remote management, demos of managing Hyper-V with and without System Center Virtual Machine Manager as well as several other demos.

Link

Link

Link

Preparing for Office 365

In this session we will look at how you can prepare your organization for Office 365, ranging from technical requirements for clients and servers to identity management. The session will focus on the core infrastructure of the Office 365 service.

Link

Link

Link

 

Other PowerShell-related sessions at the conference was An introduction to WMI And PowerShell and WMI Eventing with PowerShell by PowerShell MVP Thomas Lee.

All the other sessions from the conference is available for viewing here.

January 22, 2012 Posted by | Conferences, NIC, Windows PowerShell | , | 1 Comment

Introducing the PowerShell Network Adapter Configuration module

For a Windows administrator, working with network adapters is a common task. A common approach many companies use is configuring servers with static IP addresses (IPv4) and clients using DHCP. The IP address is just one of many properties of a network adapter, as we also have properties like subnet mask, default gateway, DNS server search order and so on. Configuring these properties is usually performed during the initial setup of a computer, either manually or by a deployment mechanism.

The configuration of a network adapter is mostly static, however, from time to time some properties might need to be changed. In example the subnet on a network is expanded to meet new requirements, and thus the subnet mask property must be updated on computers not using DHCP. Another scenario is the setup of new DNS servers, with a decision not to keep the existing DNS servers` IP addresses. I recently faced the last scenario, where several hundred servers configured with static IP addresses needed to have their DNS configuration updated. Using Windows PowerShell the task can be automated, even if we need to perform the task on 10, 100 or 1000 servers. However, the more computers a script is run against, the more important it is to implement proper error handling and logging to keep track of which computers is updated.

The above task is just one of many potential tasks for configuring a network adapter. Since I was unable to find any existing PowerShell module/library for working with network adapters on Windows systems, I decided to create a project on Codeplex:

 

The PowerShell Network Adapter Configuration module

The PowerShell Network Adapter Configuration (PSNetAdapterConfig) module is a PowerShell module for working with network adapters on Windows-based computers. The module is using Windows Management Instrumentation (WMI) to retrieve and configure properties of network adapters.

The current release of the module makes use of the following WMI-classes:

The module currently contains 4 functions:

  • Get-DNSServerSearchOrder – get the DNS client settings for a network adapter (the property name is DNSServerSearchOrder)
  • Get-NetConnectionId – get the name of a network adapter (the property name is NetConnectionId)
  • Set-DNSServerSearchOrder – change the configured DNSServerSearchOrder. This function contains two parameter sets, one for replacing the current DNSServerSearchOrder property value, the other for adding/removing IP addresses from the current value
  • Set-NetConnectionId – change the name of a network adapter. In example, change the name from “Local Area Connection” to “Server VLAN 42”

I will add functions to the module when I find time, but I also hope that people in the community will contribute by either improving the existing functions, providing suggestions or creating new functions.

When downloading a PowerShell module from the internet (typically a zip-file), beginners often get into problems because they don`t know that the file first needs to be unblocked (Right-click the zip-file->Properties->Unblock). To overcome this challenge I created a Windows installer (MSI) file which is easy to install and does not need to be unblocked:

image

The default install path is %userprofile%\Documents\WindowsPowerShell\Modules, and the user have the option to override the module path.

The installer was created using Windows XML Installer (Wix), based on Chad Miller`s blog-post Building A PowerShell Module Installer.

When the module is installed, we can use Import-Module to import the module, and Get-Command to list the available commands:

image

As we can see there is also an alias for each of the commands (functions).

By using Get-Help we can see available parameters along with their descriptions, as well as several examples:

image

The functions supports both ValueFromPipeline and ValueFromPipelineByPropertyName, which means we can leverage the PowerShell pipeline. Have a look at example 3 on the above image to see how computers can be retrieved from Active Directory using Get-ADComputer, and then piped directly into the Set-DNSServerSearchOrder function.

The functions outputs PowerShell objects, which mean we can use regular PowerShell techniques to work with the data, in example converting the objects to HTML or CSV. I typically use Export-Csv to output the data to CSV-files which in turn can be converted to Excel spreadsheets:

image

 

The functions is using a try/catch construct, using the following logic:

  1. Ping the computer, if unsuccessful the property “Connectivity” on the output object is set to “Failed (ping”)
  2. Connect to the computer using WMI, if unsuccessful the property “Connectivity” on the output object is set to “Failed (ping”)
  3. The property “Connectivity” on the output object is set to “Successful” if step 1 and 2 succeeds
  4. Retrieve or change the applicable properties using WMI

When working with a large number of computers we can use Sort-Object in PowerShell to filter the output objects based on the Connectivity property, or the sorting functionality in Microsoft Excel if the output objects is piped to a CSV-file.

 

The final example I will show is using the Set-NetConnectionId function. On a test-computer we have a network adapter named “Local Area Connection 5”:

image

Using Set-ConnectionId we can specify the subnet for which network adapter to perform the change on (the above network adapter has an IP address of 192.168.56.10) and specify the new name of the network connection:

image

When the command has run we can see that the connection name for the adapter has changed:

image

One additional feature that might be included to this function is the ability to provide a hash-table with a mapping of subnets and NetConnectionIds, which will make it easy to create a consistent naming convention for network adapters.

As a final note, all functions has a Logfile parameter, allowing us to log error message to the specified file.

 

Requirements

  • Windows PowerShell 2.0
  • ICMP (ping) and WMI firewall openings from the computer running the module to the target computers
  • Administrator permissions on the target computers

To avoid the firewall requirements, a workaround is running the functions from a PowerShell script locally on target computers using a software distribution product like System Center Configuration Manager.
Another option is to run the functions over PowerShell remoting.

 

Download and feedback

The module is available for download on the Codeplex project site http://psnetadapterconfig.codeplex.com. Please use the Discussions and Issue Tracker sites on the project site to report bugs and feature requests.

 

Resources

The functions is too long to walkthrough in a blog-post, so I will direct you to the following resources to get started working with advanced functions and modules in PowerShell:

An Introduction to PowerShell Modules by Jonathan Medd.

An Example ScriptModule and Advanced Function by Don Jones.

Ten tips for better PowerShell functions by James O`Neill.

Maximize the reuse of your PowerShell by James O`Neill.

November 22, 2011 Posted by | Remote Management, Scripting, Server management, Windows PowerShell | , , , , | 1 Comment

Test-Connection error handling gotcha in PowerShell 2.0

The Test-Connection cmdlet in Windows PowerShell was introduced in version 2.0, with the purpose of sending ICMP echo request packets ("pings") to one or more computers as stated in the cmdlet`s documentation.

The cmdlet has a number of useful parameters, for example –Count to specify the number of request packets to send (the default is 4) and –Quiet to suppress errors and make the cmdlet return either true or false:

image

The –Quiet parameter is very useful when writing a script or function where you only want to perform an operation if the target computer responds to ping requests. A basic example of using this technique:

if (Test-Connection -ComputerName doesntexist -Count 1) {            
#Proceed with script operation            
}

A few weeks ago I stumbled upon a problem when trying to use a try/catch block in a PowerShell function. What I wanted to do was to catch a ping exception when using Test-Connection. Here is the code I was running:

try            
{            
Test-Connection -ComputerName doesntexist -Count 1 -ErrorAction stop            
}            
            
catch [System.Net.NetworkInformation.PingException]            
{            
'Catched PingException'            
}            
            
catch            
{            
'General catch'            
}

To my surprise, the PingException wasn`t catched:

image

I then tried setting up a new System.Net.NetworkInformation.Ping object, to see if the PingException catch worked when using the object`s Send-method:

image

This worked, so the problem seemed to be related to the Test-Connection cmdlet.

Earlier this week I attended the PowerShell Deep Dive conference in Frankfurt, which was part of The Experts Conference 2011. In the evening the organizers set up a Script Club, where the attendees could explore various PowerShell features together, as well as getting assistance in problem solving. Together with PowerShell MVP Jeff Hicks I sat down and looked into the issue with Test-Connection. As we couldn`t figure out why the PingException catch block didn`t work as expected, we got assistance from a PowerShell team member who was attending the conference, Jason Shirk.

Jason explained to us that there is a bug with Test-Connection`s ErrorAction parameter in PowerShell 2.0, which is resolved in PowerShell 3.0 (not in CTP 1). This means my example above will work in the next version of PowerShell. Until then, Jason showed us a workaround for PowerShell 2.0:

try            
{            
Test-Connection -ComputerName doesntexist -Count 1 -ErrorAction stop            
}            
            
catch [System.Management.Automation.ActionPreferenceStopException]            
{            
try {            
throw $_.exception            
}            
            
catch [System.Net.NetworkInformation.PingException] {            
'Catched PingException'            
}            
            
catch {            
'General catch'            
}            
}

The workaround is to go into the inner exception of ActionPreferenceStopException to perform the PingException catch.

Many thanks to Jason Shirk for the assistance. For others, I would highly recommend to attend the next PowerShell Deep Dive. In addition to great presentations, you also get to network with other PowerShell enthusiasts, as well as attending the very fun and exciting Script Club in the evenings.

 

Related resources

October 23, 2011 Posted by | Windows PowerShell | , , , | 1 Comment

Hyper-V: How to unbind a physical NIC from a Virtual Switch using WMI and PowerShell

If you`re not already familiar with networking in Microsoft Hyper-V I would recommend you to have a look at this whitepaper from Microsoft, which described how networking works in Hyper-V.

The following solution will describe a problem which might occur when configuring virtual networks in Hyper-V. Consider the following scenario:

  • You`re about to configure a new external virtual network in Hyper-V using Hyper-V Manager remotely from another computer. This is a common scenario when working with the Core edition of Windows Server 2008/2008 R2.
  • When selecting the physical NIC to bind to the new virtual network, you choose the adapter which you are remotely connecting to the Hyper-V host through.

What happens in this scenario is that the Virtual Switch Management Service is binding the external Ethernet port for the selected NIC to the Microsoft Windows Virtualization network subsystem. What normally should happen next is that the converted Ethernet port should be bound to the new virtual switch you are creating. However, this never happens since the NIC you are remotely managing the Hyper-V host through is no longer available in the parent operating system. This leaves the NIC in an “orphaned” state, since you cannot use the NIC in the parent operating system, and it`s not in use by any virtual networks.

To resolve this issue, whether using the full GUI version or the Core version of Windows Server, you need to manually unbind the the Ethernet port. There is an UnbindExternalEthernetPort available on the Msvm_VirtualSwitchManagementService WMI class, which is fully documented in this article on MSDN.

To invoke the WMI method we can use Windows PowerShell. To ease the procedure I`ve created a PowerShell function you can use if you ever come into the need for manually unbinding an external Ethernet port in Hyper-V:

 

Function Select-List
{
    Param   ([Parameter(Mandatory=$true  ,valueFromPipeline=$true )]$InputObject, 
             [Parameter(Mandatory=$true)]$Property)

    begin   { $i= @()  }
    process { $i += $inputobject  }
    end     { if ($i.count -eq 1) {$i[0]} elseif ($i.count -gt 1) {
                  $Global:counter=-1
                  $Property=@(@{Label=“ID”; Expression={ ($global:Counter++) }}) + $Property
                  format-table -inputObject $i -autosize -property $Property | out-host
                 $Response = Read-Host “Select NIC to unbind”
                  if ($response -gt “”) { 
                        $I[$response] 
                  }
              }
            }
}

function Remove-HVExternalEthernetPort {

$ExternalEthernetPort = Get-WMIObject -class “Msvm_ExternalEthernetPort” -namespace “root\virtualization” | Select-List -Property name

$HVSwitchObj = Get-WMIObject -class “MSVM_VirtualSwitchManagementService” -namespace “root\virtualization”

if ($ExternalEthernetPort) {
$HVSwitchObj.UnbindExternalEthernetPort()
}
else {
throw “An error occured. Choose a valid ExternalEthernetPort from the provided list”
}

}

Note: The Select-List function is a modified version of the Select-List function available in the PowerShell Management Library for Hyper-V available on CodePlex (see link below).

You can either paste the function into a PowerShell session or save it into ps1-file and dot source it. When done you can invoke the function like this:

image

When you`ve entered the index number for the NIC you want to remove, a return value of 0 indicates the operation succeeded. Any other value indicates an error (look at the previous mentioned MSDN-article for more information).

 

More resources on managing Hyper-V using PowerShell

PowerShell Management Library for Hyper-V – this is an excellent PowerShell module for managing Hyper-V available on CodePlex

System Center Virtual Machine Manager 2012: Scripting

System Center Virtual Machine Manager 2008 R2: Scripting

Hyper-V WMI Using PowerShell Scripts

Script: Determining Virtual Switch Type Under Hyper-V

August 30, 2011 Posted by | Hyper-V, Hyper-V R2, Scripting, Virtualization, Windows PowerShell | , , | 1 Comment

How to automatically convert Windows PowerShell transcripts into script-files

In Windows PowerShell we can use the Start-Transcript cmdlet to record PowerShell sessions to a text-file. This will record both the commands you`ve run as well as the output from the commands.

Windows PowerShell MVP Jeffery Hicks recently wrote a great tip in his Friday Fun series on his blog, which tells you how to convert a PowerShell transcript into a PowerShell script file. That is, you`ll get a ps1-file which contains the commands extracted from the transcript. Combined with an object event which triggers when PowerShell exits, this can be set up to happen automatically. Jeff actually blogged another Friday Fun tip a couple years ago which describes how to set up such an object event.

Lets have a look at an example on how this would work. First we launch a new PowerShell session and executes a few commands:

image

 

When we exit PowerShell we`ll get two files in a specified log directory:

image

 

The transcript file (txt-file) contains all commands, errors and output from our session:

image

 

The PowerShell script file (ps1-file) contains a script header and the commands from our session:

image

 

This means that every PowerShell session automatically generates a PowerShell script file which can be the foundation for a new script.

To set this up you first need to copy the Export-Transcript PowerShell function from Jeff`s blog-post and add it to your PowerShell profile (Microsoft.PowerShell_profile.ps1), in addition to the following:

 

001
002
003
004
005
006
007
008
009
#Define variable for the transcript path, which we`ll use to generate the path to the ps1-file
$transcriptlog = ("C:\PS-logs\PS-Transcript_"+"{0:yyyy-MM-dd_HH-mm-ss}" -f (Get-Date)+".txt")
Start-Transcript -Path $transcriptlog | Out-Null

#Export transcript to ps1-file on exit
Register-EngineEvent PowerShell.Exiting –action {
Stop-Transcript
Export-Transcript
 -Transcript $transcriptlog -Script (($transcriptlog.Replace("Transcript","Script")).Replace("txt","ps1"
))
} 
| Out-Null

 

While this is very useful, there is a few gotcha`s to be aware of:

  • This doesn`t work if your exiting PowerShell using the X button. The PowerShell.Exiting event is only triggered when using the exit command.
  • This doesn`t work in the Windows PowerShell ISE, since that PowerShell host doesn`t support transcripts.
  • If you`ve customized your PowerShell prompt, you`ll need to tweak the Export-Transcript function to match the last letter in your prompt.

August 12, 2011 Posted by | Windows PowerShell | , | Leave a comment

Getting starting with Cisco UCS PowerShell Toolkit

Cisco – widely known as a networking infrastructure vendor – entered the blade server market in 2009. Their offering is called Unified Computing System, described by Gartner as a fabric-enabled, enterprise-class platform with good integration of networking, virtualization, management tools and storage. On the 2011 Gartner Magic Quadrant for Blade Servers they`re defined as a visionary vendor, and it will be interesting to see if they can challenge the 3 leaders Dell, IBM and HP.

The Cisco Unified Computing System is quite different from traditional blade systems, in that the server profiles (so called service profiles) is independent from the physical blade servers. An example to describe what this means is that a physical blade server might fail and be replaced, while the server profile keeps unique ID`s like MAC addresses, World Wide Names (WWN`s) and so on. If using boot from SAN rather than local disk drives, physical interaction is not required to get the system back online if a spare blade server is available.

 

The UCS core components

  • Blade Chassis – Blade server enclosure
  • Cisco UCS Manager – Embedded into the Fabric Interconnect. Provides management capabilities
  • Cisco UCS fabric interconnect – Provides networking (Ethernet/Fibre Channel) and management for connected blades and chassis`
  • Fabric Extenders – Provides connection between the interconnect fabric and the blade enclosures

A photo showing the Cisco Unified Computing System architecture is available here (cisco.com). In regards of management, all aspects of Cisco UCS can be managed through an XML API. This makes it possible for 3rd parties to offer management solutions, and integration with other products. An example of a 3rd party product is the Cisco UCS Iphone/Ipad application for managing and monitoring the system. Links for more information on the management model and the XML API is available in the resources section in the bottom of this article.

 

Cisco UCS PowerShell Toolkit

Based on a customer request from an early adaptor, Cisco provided PowerShell support for managing their UCS product through the XMP API. With the Microsoft automation strategy in mind, this was an excellent choice. It will make integration into products like System Center Orchestrator (formerly Opalis) very easy, and the also make the product attractive for enterprises. The PowerShell administration tool is available as a module part of the Cisco UCS PowerShell Toolkit.

A great way to learn using the Cisco UCS PowerShell Toolkit is downloading the Cisco UCS Emulator. This is a virtual machine image which can be imported into VMware Player or VirtualBox. When the VM is up and running you can access both the UCS Manager (http URL is shown when the VM has started) and the XML API. A great feature is that you can import the configuration from a production UCS to simulate administration changes in a lab environment.

Next, you can download the latest versions of both the Cisco UCS PowerShell Toolkit (aka UCSMPowerTool) and the PowerShell Toolkit User Guide from this website.

The installer will by default put the files in %programfiles%\Cisco\UCSMPowerToolkit:

image

CiscoUCSPS.dll is the assembly which can be imported as a module in Windows PowerShell 2.0 and later. You can either double-click LaunchUCSPS.bat or invoke StartUCSPS.ps1 from an existing PowerShell session to get started. Alternatively you can use Import-Module from an existing PowerShell session like this:
Import-Module “C:\Program Files (x86)\Cisco\UCSMPowerToolkit\CiscoUCSPS.dll”

I would suggest rather than installing to the Program Files folder (which requires administrative privileges), that Cisco generates a module manifest and install the module to the default PowerShell module directory (C:\Users\<username>\Documents\WindowsPowerShell\Modules).

When the module is imported we can use Get-Command with the –Module parameter to list all command inside the CiscoUCSPS module:

image

The current version of the module contains 149 cmdlets, so all commands are not shown in the above screenshot.

The first thing we need to do is connect to an instance of the UCS Manager. If using the Cisco UCS Emulator you can view the management  IP address when the virtual machine has started:

image

We then use the Connect-UCSM cmdlet to connect to the UCS Manager:

image

The default credentials for the UCS Emulator is config/config.

Next we can start exploring cmdlets like Get-Blade and Get-Vlan. Note that by default the cmdlets outputs a lot of information for each object, so I`ve picked out a few properties to show using Format-Table:

image

Going further it`s easy to automate things like adding VLAN and assigning it to a vNIC template:

image

 

Although the PowerShell coverage isn`t 100% yet, it`s possible to administer all aspect of the UCS directly through the XML API from PowerShell using the Invoke-XmlCommand cmdlet.

 

Resources

Cisco Unified Computing

A Platform Built for Server Virtualization: Cisco Unified Computing System

Cisco Unified Computing Forums

Automating Cisco UCS Management with Windows PowerShell

PowerScripting Podcast – Josh Heller from Cisco on UCS and PowerShell

Cisco UCS Manager XML API Programmer’s Guide

Cisco UCS Manager API Management Information Model

Cisco Developer Network: Unified Computing

Managing your Cisco UCS from an iPhone or iPad

July 23, 2011 Posted by | Scripting, Virtualization, Windows PowerShell | , , | 2 Comments

Adding printer drivers from a print server using Windows PowerShell

Managing printer drivers in a Remote Desktop Services (formerly Terminal Services) environment can be a challenge for administrators. There are many ways to ease this challenge, including third party solutions such as ThinPrint and UniPrint. When “thick” drivers are used on the RDS servers, all printer drivers must be installed locally on every server. Citrix XenApp has a printer driver replication feature which makes it possible to distribute printer drivers from a source server to one or more destination servers in a farm.

There might be situations where none of the mentioned solutions can be used for various reason, i.e. financial costs. A common way to solve this problem is to map all printer connections from a specified print server using administrative credentials during the initial setup of each RDS server. This solves the problem, but it can be time consuming as all printers that uses the same driver is being installed. Even though the driver is already installed on the local computer, it takes some time to process each printer connection.

I recently faced this challenge, as the installation of all printer connections from a few specified print servers took 30-40 minutes using a legacy script. I then wrote an advanced function in PowerShell to make the procedure more effective. This was accomplished by installing a printer connection only for unique printer drivers.
An example: A print server has 500 shared printer objects, while there is only 10 unique printer drivers. It would make more sense to add a printer connection (in order to install the driver) to 10 printer objects rather than 500, given the time consumed by installing a printer connection.

The function is available for download from here.

Sample usage and output:

image

 

image

There is a switch option added to the function called Clean. If this parameter is specified the function will also remove all mapped printer connections for the current user.

The function doesn’t`t provide any log options. However, it produces PowerShell objects, so it would be easy to pipe the output to a file.
An example on how to export the output objects to a csv-file:

image

But what about printer drivers added to the print servers after the function is run on an RDS server? One way to solve this could be adding the PowerShell function to a script-file which is set up as a scheduled task to run i.e. once a day on every RDS server.  If the scheduled task is set up using Group Policy Preferences, it will be automatically created on every new RDS server that is added later on. Beside scheduling the task to run at specified intervals, the print server administrator may also invoke the scheduled task remotely on every RDS server whenever a new print driver is added to a print server. The details on how to do this is previously described in this blog-post.

Since the function might be run several times on the same computer, it also checks if the driver to be installed is already in place on the local computer. This means that after the first run, only printer drivers added to the print server after the first run is actually installed. This makes the script more effective, and depending on the number of shared printer objects on the specified print server, it shouldn’t`t run for many seconds.

Coming back to the before mentioned example (~600 printer objects, ~50 unique drivers) where it took 30-40 minutes to install printer drivers from a print server, when using the Add-PrinterDriver PowerShell function the execution ran for 4 minutes. After the first run, subsequent executions ran for  20 seconds.

July 3, 2011 Posted by | Print management, Remote Desktop Services, Scripting, Terminal Services, Windows PowerShell, Windows Server 2008, Windows Server 2008 R2 | , , , , | 5 Comments

Enable Persistent Mode for Cluster Resource Groups using the PowerShell Failover Clustering module

In Failover Clustering in Windows Server 2008 R2, Persistent Mode is intended to allow resource groups to come online on the node which an admin last moved them to. This setting is enabled by default when a virtual machine is created with Failover Cluster Manager. If you create virtual machine via System Center Virtual Manager this setting is not enabled.

By default, cluster roles have this setting disabled, except for Hyper-V virtual machine cluster roles, which have this enabled by default. This setting is useful when the cluster is shutdown and later started, in order to better distribute the resources across the nodes and allow them to come online faster, as they were likely spread across the nodes before the cluster was offlined. Otherwise, all the resources will attempt to restart on the first nodes which achieve quorum and compete for resources. This only applies to a group if it did not failover after being placed by the administrator. If a group has failed over since the last administrator placement, it is brought online on the node which the administrator last move it to.

Reference and more info regarding the Auto Start, Persistent Mode and Group Wait Delay features is available on the Clustering and High-Availability blog.

Auto Start can be enabled/disabled in bulk by marking all Cluster Resource Groups in Failover Cluster Manager and selecting “Enable auto start”/”Disable auto start”.

For Persistent Mode the only available option in Failover Cluster Manager is to right click each Cluster Resource Group and selecting/de-selecting the checkbox for “Enable persistent mode”:

image

To change this setting for all Cluster Resource Groups in an automated fashion you can use the Failover Cluster module for PowerShell, which I wrote an introduction to here.

Here is an example on how you can do this:

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Import-Module FailoverClusters
$clustergroups = Get-ClusterGroup -Cluster cluster01.domain.local
foreach ($clustergroup in $clustergroups) {
#To enable persistent mode: x To disable persistent mode: 4294967295
$clustergroup.DefaultOwner=x
}

Although you can change the Auto Start setting in bulk in Failover Cluster Manager you might also want to do this in an automated fashion:

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Import-Module FailoverClusters
$clustergroups = Get-ClusterGroup -Cluster cluster01.domain.local
foreach ($clustergroup in $clustergroups) {
#To enable Auto Start: 1 To disable Auto Start: 0
$clustergroup.Priority=1
}

You can also change the Group Wait Delay cluster-wide property from the PowerShell Failover Clustering module, how to do this is explained in the above referenced blog-post from the Clustering and High-Availability blog.

For the next version of System Center Virtual Machine Manager I would expect that Persistent Mode is enabled by default, since Microsoft do recommend customers to enable this setting.

Update 08.12.2011: The value of the DefaultOwner property for configuring Persistent Mode is the number of the node you want to be the default owner. In example a value of 1 means the first node in the cluster.

June 3, 2011 Posted by | Failover Clustering, Hyper-V, Hyper-V R2, Scripting, Windows PowerShell, Windows Server 2008 R2 | , | 3 Comments