For Windows administrators new to Linux who wish to provide virtualized services to their end-users, my recommendation is to stick to CentOS 5.5. Being a close derivative of Red Hat Enterprise Linux (RHEL), the officially supported distribution by Microsoft, installation of the Integration Components is simplified and stability is matched to what is found when running RHEL.

Requirements

You will need the CentOS 5.5 x64 installation DVD ISO (CentOS-5.5-x86_64-bin-DVD-1of2.iso) which can be found at http://isoredirect.centos.org/centos/5/isos/x86_64/.

You will also need the Linux Integration Services 2.1 ISO (LinuxIC v21.iso) available through the Microsoft Download Center at http://www.microsoft.com/downloads/en/details.aspx?FamilyID=eee39325-898b-4522-9b4c-f4b5b9b64551.

Initial virtual machine Settings

To create the initial virtual machine, you will need to use the Legacy Network Adapter and limit yourself to a single CPU. You will also want to take time to decide how large of a VHD to allocate ahead of time as expanding a Linux partition can be a little complicated. Personally, I find 20GB to be sufficient for small, single purpose Linux virtual machines.

Installing CentOS 5.5

After booting from the CentOS ISO, you are presented with the choice to do a graphical or a text mode installation. To choose the text mode installation (as used here), simply type “linux text” at the boot: prompt and hit enter.

To navigate throughout the next portion of the text mode installation, use the Tab key to navigate between fields and the Space key to select options or hit buttons.

You will be asked if you would like to do a media test. You can safely skip this.

The initial welcome screen to the installation process.

Choose your language as appropriate.

And your keyboard.

You must then partition your VHD for Linux. As you will be starting off with a fresh VHD, you can simply choose “Use free space on selected drives and create default layout.” and continue with OK.

Be sure to hit No to continue as hitting Yes will simply bring you back to the previous screen.

As long as you have properly configured your virtual machine to use the Legacy Network Adapter, you will be presented with the opportunity to have the installation configure it for you.

Check the “Enable IPv4 support” option and hit OK to continue.

Switch to the “Manual address configuration” option and enter your IP address and netmask as appropriate.

Continue on by entering your default gateway (usually your router or your network’s default route). If you have internal DNS servers for your network, enter them here or alternatively, you can use OpenDNS.

The name of your virtual machine is defined here as the hostname.

Select your time zone and continue.

Be sure to choose a secure root password as the root user has complete access to the entire virtual machine and SSH is enabled on first boot.

For a bare minimum installation, uncheck all of the packages, check “Customize software selection” and hit OK.

Uncheck all package groups and continue. Anything you require can later be installed by yum anyway.

Installation will begin once you continue past this screen.

Once installation is complete, you will be required to reboot.

After rebooting, you will be ready to login. At this point, I recommend connecting via SSH in order to copy and paste commands.

Preparing to install the Linux Integration Components

The first thing that must be done is to update all the base packages and upgrade the kernel to the latest version. Simply run a “yum update”, then reboot.

yum update
reboot

You will need to install the required “kernel-devel”, “gcc”, “make” and “perl” packages to compile and install the Linux Integration Components. Also, I suggest installing the VIM text editor.

yum install kernel-devel
yum install gcc
yum install make
yum install perl
yum install vim-enhanced.x86_64

Installing the Linux Integration Components

Attach the Linux Integration Services ISO. Once attached, you will need to mount the cdrom. You must then copy and compile the source in a temporary folder. Finally, you will be able install the Linux Integration Components. “make” will compile the source, then “make install” will install the compiled drivers.

mkdir -p /mnt/cdrom
mount /dev/cdrom /mnt/cdrom
cp -rp /mnt/cdrom /opt/linux_ic
umount /mnt/cdrom
cd /opt/linux_ic
make
make install

The time synchronisation component is not compatible with CentOS, therefore you will need to install “adjtimex”.

yum install adjtimex

You will need to shutdown the virtual machine in order to enable the Synthetic Network Adapter and increase the number of CPUs allocated. To do so, run the shutdown command.

shutdown -h -t 0 0

Change the settings in Hyper-V once the virtual machine has completely shutdown.

Start the virtual machine and log in. You will need to reconfigure the network adapter as “eth0″ will have disapeared and a new adapter, “seth0″, will have taken its place.

The easiest way to do this is to edit the MAC address in the “eth0″ backup file to match the MAC address of the Network Adapter as displayed in the virtual machine settings in Hyper-V, then copy the backup file as “seth0″ and restart the network service. Don’t forget to also update the DEVICE line use “seth0″.

cd /etc/sysconfig/network-scripts/
vi ifcfg-eth0.bak
(edit DEVICE and HWADDR)
(save and exit)
rm -f ifcfg-seth0
mv ifcfg-eth0.bak ifcfg-seth0
service network restart

If all went well, you will find yourself with a bare minimum install of CentOS 5.5 running the latest kernel and version 2.1 of the Linux Integration Services. Fully virtualized and synthetic. You can now enjoy the many benefits of Hyper-V Linux such as the ability to shutdown the virtual machine without the root password.

Volume Shadow Copy Service error: Unexpected error calling routine RegOpenKeyExW(-2147483646,SYSTEM\CurrentControlSet\Services\VSS\Diag,…). hr = 0×80070005, Access is denied.

Inspection of the detailed tab of the event log entry will show information about the process that generated the error. Take note of the user mentioned after the “- User: Name:” portion of the bytes. To resolve this error, simply give that user full permission to the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\VSS registry key.

The DFS Namespace service could not initialize cross forest trust information on this domain controller, but it will periodically retry the operation. The return code is in the record data.

This occurs because the DFS Namespace service attempts to access Active Directory before it has completely initialized.

To resolve this issue, we simply have to force the DFS Namespace service to start after the Active Directory service has initialized. We can do this by setting the DFS Namespace service to depend on the Active Directory service as well as setting it to a Delayed Startup mode.

To make those changes, start regedit and make the following changes :

1. Navigate to the registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Dfs
2. Modify the DependOnService value and add NTDS to the list.
3. Create a new DWORD value named DelayedAutostart and set its value to 1.