Cluster support. SCVMM 2008 also
adds management support for Server 2008
failover clusters for Hyper-V. As a result,
SCVMM 2008 is cluster-aware when adding
hosts, letting you discover which clusters
are available through Active Directory (AD).
With this support you can create highly
available VMs that take advantage of PRO
on a Server 2008 cluster.
Architecture and Implementations
Architecturally, SCVMM 2008 consists of
five main components, plus PowerShell.
The first component is the Virtual Machine
Manager (VMM) service (vmmservice.exe)
itself. Next is a Microsoft SQL Server database
(either SQL Server 2005 or the free
SQL Server 2005 Express Edition for smaller
implementations) that stores configuration
information. SQL Server Express comes
as part of the SCVMM 2008 installation
package. The third component is a library,
shared on the network, that contains virtual
hard drives, ISO disk images, and stored
VMs to be used by SCVMM. An administrator console and a self-service portal round
out the picture. In addition to the major
pieces, PowerShell is an essential part of the
SCVMM server. Furthermore, every host
that’s managed by SCVMM must also have
a VMM agent installed.
You can assemble all of SCVMM 2008’s
components in a variety of ways, but most
installations fall into one of three major
types: workgroup, corporate, or enterprise.
In the workgroup configuration, all components
reside on one server. This setup is typical
in small-to-midsized businesses (SMBs)
and in test labs. The corporate setup, which
Figure 1 shows, separates the components
on their own servers to increase scalability
and fault tolerance. The enterprise configuration
that Figure 2 illustrates expands on
the corporate configuration by leaving the
SCVMM and SQL Server systems centrally
located but scattering library and host pairs
to different geographical locations.
PowerShell Benefits
Like Exchange Server 2007, SCVMM depends
on PowerShell to perform its actions. SCVMM
is essentially a sophisticated PowerShell script generator. This architecture has its
detractors—for example, it’s probably not
as fast as making API calls in a lower-level
language—but it adds a tremendous amount
of flexibility. Every SCVMM action generates
and executes a PowerShell script. Every
wizard has a PowerShell button on the summary
dialog that lets you see (and copy) the
script that will be executed. You can modify
the script for your own purposes, thus never
having to step through the wizard again. A
side benefit is that each wizard also teaches
you PowerShell through the programmer’s
time-honored learning method: modifying
someone else’s code.
Yet another benefit to the PowerShellcentered
design is SCVMM’s job-oriented
approach. Because every action you perform
executes a script, the script’s execution
is tracked and logged as a job in the VMM
console’s Jobs view, as Figure 3 shows. If a
job fails, you can re-execute it.
Installation
If you’re just starting to work with SCVMM,
one of your first tasks is to build up its library,
which is a catalog of the resources you use
to create your VMs. These
resources fall into three categories:
file-based resources,
templates, and stored VMs.
File-based resources are
the library’s main resource
type, and they include CDROM
or DVD images in ISO
format that you can attach
to build a VM instead of a
physical disk, existing Virtual
Hard Disks (VHDs) that have
been sysprepped to create
new instances of themselves,
PowerShell scripts, and virtual
floppy disks for some OS
boot requirements. SCVMM
can automatically create a
sysprepped library VHD from
an existing VM. The second
resource type in the library is
templates that contain hardware
profiles and guest OS
profiles. These resources let
you develop a standardized
set of hardware (memory size,
processor type, virtual CDROM
or DVD with appropriate
ISO disk image attached) and OS configurations (OS version,
license key) to quickly create a new
VM. The third resource type in the
library is complete VMs that you
can quickly deploy onto a host
server.
Installing SCVMM 2008 is a
straightforward process, especially
compared with the installation
procedure for the 2007 version.
In the earlier version, checks for
prerequisites occurred throughout
the installation. If you were missing
a component, you had to back
out of the installation process, add
the component, and start over. In
contrast, the SCVMM 2008 installer
makes hardware and software prerequisite
checks at the beginning of
the installation process. In addition,
the new Wizard format lets you see
where you are in the process.
SCVMM requires SQL Server,
but if you don’t have a large number
of machines to manage you
can use SQL Server Express,
which is included. You also
need the Microsoft .NET
Framework 3.0 and Windows
Automated Installation
Kit (WAIK) 1.1, as well
as PowerShell, if you’re
going to install the Administrator
Console on a system
other than the VMM system.
The VMM server connection
uses port 8100, agent
connections for hosts and
library servers use port 80,
and file transfers (e.g., for
the creation of VMs from
library VHDs) use port 443.
SCVMM 2008 can’t be
installed on Server Core.
This limitation is understandable
because several
of SCVMM’s features
(e.g., PowerShell, the rich
user interface) don’t run
on Server Core. However,
Server Core includes the
most secure implementation of Hyper-V,
which means that you can’t run SCVMM
on a highly secure Hyper-V host server or
cluster. (Note that you can still manage
Server Core hosts or clusters.) This short-coming probably isn’t a big deal for large
companies that can run all the SCVMM
components on separate systems, but
it’s an important consideration for SMB
implementations.
Configuration
SCVMM’s Administrator Console uses the
System Center Framework user interface,
which resembles Microsoft Outlook’s layout,
with a scope of what you’re looking at on the left, specifics in the middle,
and actions for those specifics on the right, as
you can see in Figure 3. The left-hand pane is
divided into a treeview on the top and large
buttons for the major SCVMM views on
the bottom. Those primary SCVMM views
are Hosts, Virtual Machines, Library, Jobs,
and Administration. The middle pane
focuses on the objects that match the view
you select in the scope pane. The upper
window can contain a list of hosts, VMs,
library files, jobs, or administrative options.
The lower window contains the properties of
the object that’s selected in the upper window.
In Figure 3, for example, the lower window
displays the progress of the individual
steps in the Create virtual machine job
selected in the upper window. The right
pane—the action pane—shows a list of
actions you can perform on the object
you’ve selected. It contains all the actions in
the right-click context menu for an object,
plus general actions you can take at any
time.
Whether you’re creating a new VM
from Hyper-V or from SCVMM 2008, the
first thing you notice is that the mouse
doesn’t work in the VM’s console session.
For the mouse to work and the console to
have full functionality, you need to install
Server 2008 Hyper-V’s Integration Services
on the VM. (Server 2008’s initial Hyper-V comes with a version of Integration Services
already installed, but later versions of
Hyper-V have made it incompatible.) You
need to control the VM without a mouse to
install Integration Services.
If you use Remote Desktop to log on to
the VMM console (instead of having the
console installed locally on your system),
the process is even more cryptic and subtly
different from what you’ve done in the past.
You might think that removing management
on the VM and connecting to the VM via
Remote Desktop is a workaround for this
problem, but it isn’t. Without the installation
of Integration Services, the VM doesn’t have
a working network adapter and therefore
lacks remote management. However, you
can build a sysprepped image with Integration
Services preinstalled and then store it
in the library as a VHD from which to base
new VMs. This way, the mouse functions
on the VMs from the start. John Howard,
senior program manager on the Hyper-V
team, comes to the rescue with his blog
post “Controlling Hyper-V VMs in Virtual
Machine Connection over TTS/Remote
Desktop without a mouse” at blogs.technet.com/jhoward/archive/2008/03/23.aspx,
which helps you through mouse-less
operation.
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