As server virtualization becomes more popular, IT professionals are quickly
realizing that migrating some of their company’s resources to a virtualized
infrastructure is only part of the challenge. After virtualizing the resources,
you have to manage them—and handling virtualized servers isn’t the same as
administering physical servers. A physical host server and perhaps a host OS
add an extra layer or two of software between virtual machines (VMs) and the
real world. You can create, alter, and remove VMs with a speed and flexibility that’s unheard
of compared with what you can do with physical servers, but traditional toolsets don’t have
the facilities to handle this added coating of complexity.
Microsoft created System Center Virtual Machine Manager (SCVMM), which is a component
of the company’s suite of System Center products, to manage a virtual infrastructure;
SCVMM 2008 improves on the original version. SCVMM was designed to integrate into
System Center Operations Manager (SCOM) 2007 SP1, and if you’re already using SCOM
you can take advantage of a significant new feature in SCVMM 2008 to optimize your virtual
resources.
If you’ve installed the Hyper-V role on Windows Server 2008 and are already using
Hyper-V Manager, you might wonder whether SCVMM 2008 can benefit you. Hyper-V
Manager provides a simple interface that lets you control the configuration of VMs, one
machine at a time. You can create a VM, start it, change its settings, take snapshots of it,
export it, import it, stop it, and delete it. SCVMM does all that and far more.
SCVMM 2008 Features
SCVMM is a solution for all aspects of
managing a virtual infrastructure. New
features in SCVMM 2008 include Hyper-V
integration, Performance and Resource
Optimization (PRO) and SCOM integration,
VMware ESX Server support, a new
delegated administrator role, and cluster
support.
Hyper-V integration. One of the most
significant new attributes of SCVMM 2008 is
Hyper-V integration. Hyper-V is Microsoft’s
virtualization technology that uses a hypervisor—
a thin layer of software between the
hardware and the OS that lets multiple OSs
run on a host computer at the same time.
Hyper-V features 64-bit architecture and
therefore 64-bit VM support, multiprocessor
VMs, and virtual switched networking—
which is a big step beyond Microsoft Virtual
Server 2005. SCVMM 2008 manages all
aspects of Hyper-V hosts and VMs.
PRO and SCOM. SCVMM 2008 has a
useful feature in its PRO package, which tackles
the problem of balancing VM loads across
multiple servers. PRO is tightly integrated
with SCOM and requires SCOM to function.
You must install SCOM agents on all hosts
and VMs, and you must also install SCVMM
2008 and PRO management packs. With
PRO in place and configured, SCOM will
pass alerts on to SCVMM 2008. A PRO “tip”
noting the problem and a recommended
action appears on the SCVMM console. You
can either manually approve the tip so that
PRO executes it, or, if you set auto-approve,
let PRO take action on its own.
A popular example of a common
resource-management challenge is when
a VM runs out of resources because a host
becomes overloaded. SCOM detects the
overload, passes it to SCVMM 2008, and
generates a PRO tip indicating that you
should move the VM to another host. (PRO
functions on Server 2008 failover host clusters
only.) You determine the recommended
new host by using the Intelligent Placement
feature first introduced in the previous
version of SCVMM. If you turn on autoapprove,
the automation level sets to Critical
Only, which means that only PRO tips with
a critical severity level are automatically
implemented. This setting auto-manages
your host cluster in such situations.
PRO’s capabilities also leverage
SCVMM 2008’s management of VMware
ESX Server. For example, you can define a
policy in PRO that triggers a VMotion VM
migration. Thanks to its integration with
SCOM, however, PRO goes beyond just migrating a heavily used VM to another
host. It understands what’s happening
with the entire stack on Windows VMs—
the host, the VM, and applications running
on the VM.
IT pros sometimes lose sight of the fact
that ultimately it’s the applications and their
health that count rather than the infrastructure.
With PRO’s holistic view of the virtual
environment, you can define policies and
rules that take action on a host (e.g., add
more processor capacity to the VM) because
the application requires it, not just because
the VM shows high utilization.
PRO is also extensible, so Microsoft is
working with its hardware and software
partners to make PRO’s tips intelligent with
regard to the application and hardware configuration.
You can get practical information
about configuring SCVMM to work with SCOM and then with PRO at blogs.technet
.com/m2.
VMware ESX Server support. SCVMM
2008 can now manage VMware ESX servers
through its integration with VirtualCenter.
What this management means is that
SCVMM 2008 can control VirtualCenter’s
popular strengths, such as VMotion, as
well as apply its own features, such as Intelligent
Placement and PRO, to VMware VMs.
(Intelligent Placement is a feature available
in both SCVMM 2007 and SCVMM 2008
that selects the correct host based on the
workload you define for a VM rather than
selecting an available host, creating the VM,
and hoping it fits.) For example, SCVMM
2008’s ESX management is accomplished
through the management of VirtualCenter
itself, not the direct administration of the
ESX hosts. This is because ESX management APIs are available only through VirtualCenter.
Therefore, VirtualCenter Server is
a requirement for managing VMware hosts
and VMs.
Delegated administration. The delegated
administrator is a new role available
to manage hosts and VMs in SCVMM 2008.
A delegated administrator can perform all
the functions of a full administrator but
only on a subset of objects. This kind of job
is useful for people who need to perform
administrative functions on some but not
all hosts managed by SCVMM. This role has
broader administrative rights than the selfservice
user role. You can control the selfservice
user role according to what types
of functions are allowed on a per-VM basis,
whereas the delegated administrator has
full rights on a predefined scope of host
servers and libraries. For example, you could delegate administration rights to manage
hosts and libraries for a particular region.
Continue on Page 2
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.
Continue on Page 3
Microsoft designed SCVMM and its
administrative console to manage hosts and VMs in the same domain, the same
forest, or a different forest joined through a
forest trust. It’s possible but extremely difficult
to use a non–domain-joined console
to manage domain-joined resources. John
Howard also has blog posts on this topic,
but you don’t want to attempt the procedure
unless absolutely necessary. If you
have VMs to manage in multiple forests,
I strongly recommend that you establish
forest trusts (rather than external trusts)
between the forests.
Modern Virtual Infrastructures
VMs are much easier to provision than
real machines, but once they’re in production,
they have many of the same
lifecycle issues that physical servers have.
For instance, you must patch them and
back them up. (For information about
patching VMs, see the sidebar “Microsoft’s
Offline Virtual Machine Servicing Tool.”)
SCVMM isn’t a silver bullet for practicing
lifecycle management on your production
systems. It doesn’t address whether a system
should still be up and running, shut
down and stored in the SCVMM library,
or simply deleted. Your operational practices
must cover the server lifecycle issues,
regardless of whether the servers are virtual
or physical.
SCVMM is currently in public beta; you
can register for it at connect.microsoft.com.
It is scheduled to be released by the end of
2008.
For all the talk about virtualization, the
adoption of it is still low. One of the biggest
barriers to a wider acceptance of virtualization
is the cost of building a productioncapable
virtual infrastructure. IT budgets are
so tight that bottom-line costs for a solution
are extremely important. With Server 2008,
Hyper-V, and SCVMM 2008 and its integration
with SCOM, Microsoft has built a compelling
case for constructing a modern virtual
infrastructure at a reasonable price.