Welcome to Hyper-V 3.0 (Part 3) - A Hyper-V 3.0 virtual machine deep-dive

If you would like to read the other parts in this article series please go to:

Introduction

A few months ago, Microsoft made available the first preview of the upcoming Windows Server 8 product, which includes a first real look at Hyper-V 3.0. Much has been written about the new features and capabilities coming in Hyper-V 3.0, but I wanted to start seeing it in action.

In part 1 of this series, you got to see the full process of creating a new virtual machine. At the end of part 1, we had a fully functioning VM. In part 2, we left off at configuring the number of virtual processors and that’s where we’ll pick up here.

Virtual machine configuration

Hyper-V also allows you to specify some processor compatibility settings, as shown in Figure 6. These settings are especially useful if you’re running Hyper-V on different versions of the same processor family.

Migrate to a physical machine with a different processor version. This option should not be construed as enabling the ability to seamlessly migrate virtual machines between different processor platforms, such as from AMD to Intel and vice versa. Rather, it means that you can migrate a virtual machine from an older processor to a newer one as long as the processors are from the same vendor. When migrating between hosts with supported processors, no restart of the virtual machine is necessary.
Run an older operating system, such as Windows NT. The second checkbox, Run an older operating system, such as Windows NT, hides unsupported processor features from older operating systems so that they can run under Hyper-V. Bear in mind that this option simply gets these operating systems to function. It does not mean that Microsoft will support them.

Figure 1: Change processor compatibility settings

I previously discussed NUMA, so I’m not going to repeat it here, but, for completeness, wanted to include Figure 2.

Figure 2: Change processor NUMA settings

As mentioned in Part 2, you can’t boot a Hyper-V virtual machine from a SCSI- or Fibre Channel-based virtual hard disk, so IDE remains a critical component and gets a configuration page like the one shown below in Figure 3. You’re able to add either virtual hard drives or virtual DVD drives to your virtual machine. Do so by clicking the Add button on the configuration page. You can add up to two devices per IDE controller.

Figure 3: Configure the IDE controller

If you have an OS installed inside your Hyper-V virtual machine, you probably have an IDE-based virtual hard disk installed like the one shown below in Figure 4.

Controller. To which virtual controller would you like to attach the device? You can choose from any installed IDE, SCSI or Fibre Channel controllers.

Location. On which controller port/location should the new device be attached?

Media. Do you want to connect virtual media – for example, a virtual hard drive – to this device or will this be configured as a pass-through to physical hardware?

Sometimes, a service needs direct access to physical disks and won’t support the use of a VHD/VHDX. Or, the service simply needs so much disk space that presenting a physical volume makes more sense. For example, while I was creating my Data Protection Manager 2010 course for Train Signal, I needed to use a storage volume that was huge in size and based on physical – not virtual – disks.

A pass-through disk allows you to mount a physical volume to a Hyper-V virtual machine. In my DPM course, I used a pass-through disk to act as the storage pool device that I needed to use for my lab scenarios. There are, however, some serious drawbacks to the use of pass-through disks.

Pros

Carries a performance gain over virtual disks since there is no abstraction taking place. The virtual machine has direct access to the disk.

Cons

Not portable at all. It’s tougher to move the storage to another server.
You cannot take snapshots of a pass-through disk.
The Hyper-V VSS writer cannot back up a pass-through disk. If you’re backup software uses this common protection technique, you’ll need to find alternative methods – such as installing a backup agent inside the virtual machine itself – for protecting the contents of the pass-through disk.

Figure 4: Change the settings for the selected hard drive

I won’t say too much about the CD/DVD drive option shown in Figure 5. This is a lot like what you just saw regarding virtual hard drives.

Figure 5: Change the configuration of the DVD drive

If you have a virtual SCSI adapter installed inside your Hyper-V virtual machine, you can add hard disks to this adapter; up to 64 hard disks per adapter are allowed.

Figure 6: Make necessary changes to the included SCSI controller

The network component is another critical part of your virtual machine’s configuration and its properties page can be found in Figure 7.

Virtual switch. Choose the virtual switch to which this virtual network adapter should be connected. Virtual switches can be managed using the Hyper-V Manager.
VLAN ID. Enable virtual LAN identification. If you want to enable VLAN identification, select this checkbox and provide a VLAN value in the box provided.
Bandwidth management. Enable bandwidth management. You can control how much bandwidth is consumed by this virtual machine by enabling the appropriate checkbox and then providing values for both minimum and maximum bandwidth in megabits per second.

Figure 7: Configure network settings

There are also a number of hardware-based acceleration features you can choose when you’re working with the right hardware. These features are:

Virtual Machine Queue (VMQ). VMQ is a feature which, when enabled, creates a dedicated queue on a host’s physical network adapter for each virtual network adapter that has requested a queue. VMQ can reduce processing overhead in packet routing and make the networking process more efficient. VMQ is most useful for virtual machines that have a heavy network workload. Since they should be considered a scarce resource, you shouldn’t enable VMQ for every virtual machine.
IPsec Task Offload. When a network adapter supports the feature, IPsec task offload can reduce some of the processor performance hit associated with IPsec encryption algorithms. This can improve overall server scalability.
Single-Root I/O Virtualization (SR-IOV). SR-IOV allows the system to partition PCIe-based hardware resources into virtual interfaces. In short, a single PCIe device can be made to appear as multiple devices. I’ll provide more information about SR-IOV in a future post.

Figure 8: Manage network adapter hardware acceleration features

In Figure 9, you’ll see that there are a number of advanced networking features at your disposal.

MAC address. You can choose between a dynamic and a static MAC address for this virtual machine. If you’re having MAC address issues, try using a static address.
Enable MAC address spoofing. In some configurations, such as when using Network Load Balancing, you may have to spoof the MAC address in order for the service to operate.
DHCP Guard. Allows administrators to protect Hyper-V virtual machines from rogue DHCP servers.
Router Guard. Allows administrators to protect Hyper-V virtual machines from rogue router advertisements.
Monitor Port. Enhance troubleshooting by monitoring the network traffic than enters and exits a virtual machine.

Figure 9: Manage network adapter advanced features

The serial port is certainly a legacy holdover, but is still important. In Figure 10, you can see the settings that are provided to manage serial ports. The virtual COM port can either be connected to nothing or connected via a named pipe to a remote computer.

Figure 10: Change serial port settings

Finally, you have the option to manage how the floppy drive in the virtual machine will behave, if it’s installed at all. By default, the floppy drive has no media, but you can also create and use a virtual floppy disk if you need to do so.

First of all, you need a blank virtual floppy disk. To create a new blank virtual floppy disk, open the Hyper-V Manager. Go to the Actions menu and choose New > Floppy Disk (Figure 11).

This opens the Create Virtual Floppy Disk dialog box that you see below in Figure 12. In this window, provide a file name that you’d like to associate with the new blank floppy image.

With the new floppy image created, you now need to “insert” the image into one of your virtual machines. Open the settings page for the target server and choose the Diskette Drive option. On the properties page for that device, choose the Virtual floppy disk (.vfd) file option and locate the floppy image. Once you’ve done so, click the Open button.

You can now use the new floppy disk image just as you would a real blank floppy.

Figure 11: Change the media that’s loaded in the virtual floppy drive