Category Archives: Administration

Installing Ubuntu 14.04 LTS as a Generation 2 Hyper-V guest

Since Microsoft release Windows Server 2012 R2 Hyper-V have had two different generations of virtual machines. The old “Generation 1” and the new “Generation 2”. Microsoft added generation 2 to get rid of the old stuff that really doesn’t make sense in a virtual world. And also to add new stuff. Generation 2 virtual machines provide the following new functionality:

  • PXE boot by using a standard network adapter
  • Boot from a SCSI virtual hard disk
  • Boot from aSCSI virtual DVD
  • Secure Boot (on by default)
  • UEFI firmware support

As can be expected all of these features worked fine straight away with Windows 8 (64-bit) and Windows Server 2012 or later. But they did not work well with Linux. Until now.

The fresh Ubuntu 14.04 LTS release works fine with and can be installed into a generation 2 virtual machine in Hyper-V. There is only one thing you need to know – Secure Boot has to be disabled. Hyper-V enables secure boot by default so if you just click through the wizard to create a VM it will not work. You have to disable Secure Boot.

Here’s the PowerShell way to check if Secure Boot is enable for your VMs:

Get-VM | Get-VMFirmware

To disable Secure Boot for a specific VM (‘TrustyTahr’) use this:

Get-VM -Name 'TrustyTahr' | Set-VMFirmware -EnableSecureBoot Off

Now you can install Ubuntu in a generation 2 Hyper-V machine. It just works. And even though I have not done any valid tests the gen 2 Ubuntu machine feels a lot snappier than on old one.

Basic inventory of HyperV virtual machines using PowerShell

Working at large scale with thousands of servers customers often asks for a list of machines with various properties for each machine.

Most of the time the customer want this information in an simple format (read CSV, the World isn’t as advanced as you like!) so that they can use it internally. In this blogpost I will show how you can get the information about memory, CPU count etc for a set of Hyper-V machines from Virtual Machine Manager via PowerShell.

Start a PowerShell command line and load the PowerShell Snap-In for Virtual Machine Manager.

Add-PSSnapin -Name Microsoft.SystemCenter.VirtualMachineManager

Now we can work with the commands made available to us by the Snap-In, if you want to find all the commands that are available issue:

Get-Command -Module Microsoft.SystemCenter.VirtualMachineManager

So let’s begin by loading information about all our machines from the VMM host into a variable named $VMs

$VMs = Get-VM -VMMServer hyperv-vmm01.sth.basefarm.net

What the above command does is to load all of the VMs on the host HYPER-V-01.mydomain.com into the variable $VMs. This means we will only do one call to the server which avoid generating unnecessary load.

Now let’s check how many machines we have:

$VMs.Count

And now that we know we have machines to query, let’s find out what attributes exists (things we can get into our output)

$VMs | Get-Member -MemberType Property

For example, to find all macines that are powered off:

 $VMs | where { $_.Status -eq 'PowerOff' } | select VMHost, name , Memory, CPUCount , Status

The above example adds some complexity to the command, but it is to filter so we only see machines that have the status is ‘PowerOff’.

Now let’s get what we wanted from the beginning, a list of machines for a specific customer. The list should include name of the VM host, VM name, memory, number of CPUs and current status.

 $VMs | where { $_.Name -Match 'CUST*' } | select VMHost, name , Memory, CPUCount , Status

This will list all machines who’s name begins with ‘CUST’. So we now have found what we wanted!

But instead of copying & pasting this we want to write the result to a CSV file so we can send that to the customer. Let’s make that easier by getting the output of the above command into a variable named $result

 $result = $VMs | where { $_.Name -Match 'LFO*' } | select VMHost, name , Memory, CPUCount , Status

Now our ‘report’ is stored in the $result variable and we can use standard PowerShell to export it to a CSV file:

$result | Export-Csv -NoTypeInformation -Delimiter ';' .\report.csv

Now our report is available in a CSV file on the file ‘report.csv’ (in the current directory)

A very basic way of getting your Hyper-V inventory out!

Quick way to name your NICs in Windows Servers

If you, like me, manage many servers, it’s essential to name network adapters in a way that makes it easy to troubleshoot issues when they arise.

In complex networks with thousands of servers and all servers connected using multiple paths a consistent naming standard is very important!

PowerShell and the cmdlets available in Windows Server makes naming adapters a breeze. The servers we usualy deploy have built in four (4) port network adapters. We like to name the Windows NICs the same as is the default in Linux; eth0, eth1, etc.

In the following example we name the adapters eth0, eth1, eth2 and eth3 in Windows. The NIC with the lowest MAC address gets the name eth0 etc. (If you prefer to to start naming adapters from eth1 change the variable $NICs to 0):

 $NICs = -1
 Get-NetAdapter Etherne* | Sort-Object MacAddress | % { Rename-NetAdapter -InterfaceAlias $_.InterfaceAlias -NewName eth$NICs }

PowerShell really makes life easy 😉

Default = PowerShell

In a earlier blog post I wrote about how to generate passwords using PowerShell. Here comes another PowerShell advice for you.

Now that Windows Server 2012 will be officially available many servers will be installed as ‘core’ servers. That is in itself a very good thing. The bad thing about it is that Microsoft have set the default command Shell to be CMD.EXE. Nothing wrong with that per se but these days administrators should go PowerShell all the way. If you’re like me and want PowerShell to be your default shell even in core servers, do this to make PowerShell your default shell:

$Path = 'Microsoft.PowerShell.Core\Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\winlogon'
 Set-ItemProperty -Confirm -Path $Path -Name Shell -Value 'PowerShell.exe -noExit -Command Set-Location "$env:userprofile"

The next time you login to the machine you will get PowerShell as the default shell 🙂

Windows Server 2012 is coming!

A week from today Microsoft releases Windows Server 2012. For ordinary computer users this release may not mean a lot, but for us working with running large server systems it will be a game changer.

Fundamental parts of the Windows Server operating system have been changed. Some changes are visible such as the lack of a graphical user interface on a standard server. Other changes are less visible; new storage options, filesystems etc.

A very big change for operations is that PowerShell really have moved into the core of managing Windows. This will allow us to automate more than before, with ease!

I won’t go into all the details here but if you want to be part of the launch event for Windows Server 2012, setup a reminder here.

Generate passwords using PowerShell

The other day I needed to generate some 1400+ new user passwords. Being a lazy person I figured that PowerShell could rescue me. This is what I did to check that my idea worked:

PS C:\> Add-Type -AssemblyName "System.Web"
 PS C:\> [System.Web.Security.Membership]::GeneratePassword(10,2)
 35&OjFtM^k

As you can see this generates a password that is 10 characters in length and contains at least 2 non-alphanumeric characters. Now all I needed was to iterate this 1400 times and then output the result to the clipboard, simple as pie:

PS C:\> 1..1400 | % { [System.Web.Security.Membership]::GeneratePassword(10,2) } | clip

And that is a 1400 new passwords stored in the clipboard. I can now paste these or pipe them into a set password routine.