Hyper-V and Networking

[kattman]

Hyper-V

Introduction

Microsoft Hyper-V, codenamed formerly known as Windows Server Virtualization, is a hypervisor-based virtualization system for x64 systems.Hyper-V is installed as an add-on role within the 64-bit version of Windows 2008 Enterprise and Database Center editions.

Windows 2008 Server Roles are disabled and there are limited Windows Services. Configuration of the actual OS, physical hardware and software is done using shell commands. A new menu driven interface does simplify initial configuration, and some freely downloadable script files extend this concept.

why it is useful

Administration and configuration of the virtual server (or guest OSes) is done using software installed on a Windows Vista PC, or another Windows 2008 Server, with the Hyper-V administration MMC program plug-in. Other administration / configuration of Windows 2008 Core server can be done on a remote Windows Desktop or Server by redirecting (certain) Microsoft Management Console (MMC) pointing at the Core Server. This allows easier point and click configuration.

The Host runs each Guest in a separate , and each guest runs in its own premises , mostly unable to access features of the Host. Hypervisor and Microsoft's Hyper-V allows the Guest to call into well-defined services of the host and let the Host handle the requests .Thereby increasing performance and improving resource allocation. The Guest OS is now virtualization aware and can do things differently when it is run from within a virtual session rather than on bare-metal.

When the OS is not on hyper-v, the OS needs a page file to swap physical memory with disk-based memory. However, when the OS is running within a VM as a guest, the host OS probably already has its own page file. So, physical hardware get reduced. This would avoid the double layer of IO that guest machines currently have to go through in order to page memory and process will complete fast.

[kattman]

Architecture

Hyper-V supports isolation in terms of a partition. The Hyper-V is used Windows Server 2008 operating systems for its operation. Windows Server 2008 required to run on parent partition.Now the operating system on parent partition has direct access to the hardware devices.

The parent partition then creates the child partitions which host the guest operating system.A child partition can create further their own
child partitions.Parent partition creates child partitions using the hypercall API, which is the application programming interface exposed by Hyper-V.
Multiple child partitions can simultaneously on a single, physical server. Each child partition is capable of running a different operating system.

A virtualized partition does not have access to the physical processor, nor does it handle its real interrupts. Instead, they have a virtual view of the processor and run in Guest Virtual Address, which depending on the configuration of the hypervisor.

The hypervisor handles the interrupts to the processor, and redirects them to the respective partition. Hyper-V can hardware accelerate the address translation between various Guest Virtual Address-spaces by I/O Memory Management Unit.

Child partitions do not have direct access to hardware resources, but instead have a virtual view of the resources, in terms of virtual devices. Any request to the virtual devices is redirected via the VMBus to the devices in the parent partition, which will manage the requests. The VMBus is a logical channel which enables inter-partition communication. The response is also redirected via the VMBus. If the devices in the parent partition are also virtual devices, it will be redirected further till it reaches the parent partition, where it will gain access to the physical devices. Parent partitions run a Virtualization Service Provider (VSP), which connects to the VMBus and handles device access requests from child partitions. Child partition virtual devices internally run a Virtualization Service Client (VSC), which redirect the request to VSPs in the parent partition via the VMBus. This entire process is transparent to the guest OS.

the following operating systems are initiated :

• Windows Server 2008
• Windows Server 2003 SP2
• Windows Server 2000 SP4
• Windows HPC Server 2008
• SUSE Linux Enterprise Server 10 SP1/SP2
• Windows Vista SP1 (except home editions)
• Windows XP SP2/SP3

System requirements :

1. An x64-based processor running an x64 version of Windows Server 2008 Standard, Windows Server 2008 Enterprise or Windows Server 2008 Datacenter.
2. Hardware-assisted virtualization. This is available in processors that include a virtualization option; specifically, Intel VT or AMD Virtualization (AMD-V, formerly code-named "Pacifica").
3. NX bit-compatible CPU must be available and Hardware Data Execution Prevention (DEP) must be enabled.
4. Memory minimum 2 GB. (Each virtual OS requires its own memory, and so realistically much more.)
5. Windows 2008 Standard (64 Bit) Hyper-V Core requires approximately 3 GB of disk space (installed size)
6. Windows 2008 Standard (64 Bit) Hyper-V full GUI product requires approximately 8 GB of disk space (installed size)
7. Windows 2008 Standard (64 Bit) Hyper-V full GUI or Core supports up to 31 GB of memory for running VMs, plus 1 GB for Hyper-V Parent OS. [1]
8. Windows 2008 Standard (64 Bit) Hyper-V full GUI or Core supports up to 4 processors with 1, 2 or 4 cores
9. Windows 2008 Standard (64 Bit) Hyper-V full GUI or Core supports up to 128 "Guest OSes" [2]
10. Windows 2008 Standard (64 Bit) Hyper-V full GUI or Core supports 32-bit (x86) and 64-bit (x64) Guest VMs

The stand-alone Hyper-V Server does not require an existing installing of Windows Server 2008 and has a minimum memory requirement of 1Gb and disk space requirement of 2Gb.

[kattman]

Networking with Hyper-V

First to set the Windows Server 2008 installation on a system with one network adapter you will see this under Network Connections:

Open the Hyper-V Manager and in the action pane (right), choose Virtual Networks. Since you can create three types of networks. And you choose the wrong, or the wrong order, you connect with the Hyper-V host and can be lost.

Parent and child partitions without partitioning virtual networks

The above picture is that the NIC on the left. You do not default NIC for the child and partitions in the above picture is not connected.
In Virtual Networks you have the choice of three kinds of networks:

• Private Network
• Internal Network
• External Network

.

As you can see the parent partition (host operating system in Virtual Server lingo) is now using a virtual network adapter to connect to the physical network. If you look at network connections on the parent you will now see the original network adapter and a new virtual network adapter:

[kattman]

private network

A private network is intended for communication between different VM within a Hyper-V servers. Through this network can not be communicated with the host.

A Virtual Private Network

See a virtual network as an internal switch. The VM's are different each with a paw in the switch, but the switch is not connected to the parent partition.

internal network

An internal network goes a step further. This is essentially the same as a private network, but with the difference that the host on the virtual switch is connected. This is a virtual NIC, not the physical NIC, as the VM in this case nothing to do with it.

An Internal Virtual Network


external network

In an external network, things are different. There is the physical NIC with a paw in the virtual switch and the parent partition with a virtual NIC in the virtual switch. The VM's have a direct connection to the outside.

An External Virtual Network

If you have installed Hyper-V and you have a fixed IP address to the outside world you must be careful. Go configure your external network then yes of Figure 1 to Figure 4. You dedicated IP lapsed because the connection is gone. From the host is given a new NIC emerged with new settings. And they are so default DHCP. Connecting road, road IP number, no more connection to the host.

Unlike with Virtual Server, Hyper-V only binds the virtual network service to a physical network adapter when a virtual switch is associated with the physical network adapter in question. The advantage of this is that you avoid the performance overhead involved with having this service enabled on network adapters that are not associated with virtual network switches