Windows Server 2008 R2 Unleashed (15 page)

template. Actual guest session resources are not permanently allocated but rather allocated

and dedicated at the time of logon.

VDI is covered in more detail in Chapter 25.

Improvements in Clustering and Storage Area Network Support

37

Improvements in Clustering and Storage Area

1

Network Support

Although clustering of servers has been around for a long time in Windows (dating back

to Windows NT 4.0, when it was available, but really didn’t work), clustering in Windows

Server 2008 R2 now not only works, but also provides a series of significant improvements

that actually make clustering work a whole lot better.

As IT administrators are tasked with the responsibility of keeping the network operational

24 hours a day, 7 days a week, it becomes even more important that clustering works.

Fortunately, the cost of hardware that supports clustering has gotten significantly less

expensive; in fact, any server that meets the required specifications to run Windows Server

2008 R2, Enterprise Edition can typically support Windows clustering. The basic standard

for a server that is used for enterprise networking has the technologies built in to the

system for high availability. Windows Server 2008 R2, Enterprise Edition or Datacenter

Edition is required to run Windows Server 2008 R2 clustering services.

Clustering is covered in detail in Chapter 29, “System-Level Fault Tolerance

(Clustering/Network Load Balancing).”

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No Single Point of Failure in Clustering

Clustering by definition should provide redundancy and high availability of server

systems; however, in previous versions of Windows clustering, a “quorum drive” was

required for the cluster systems to connect to as the point of validation for cluster opera-

tions. If at any point the quorum drive failed, the cluster would not be able to failover

from one system to another. Windows Server 2008 and Windows Server 2008 R2 cluster-

ing removed this requirement of a static quorum drive. Two major technologies facilitate

this elimination of a single or central point of failure, which include majority-based

cluster membership verification and witness-based quorum validation.

The majority-based cluster membership enables the IT administrator to define what

devices in the cluster get a vote to determine whether a cluster node is in a failed state

and the cluster needs to failover to another node. Rather than assuming that the disk will

always be available as in the previous quorum disk model, now nodes of the cluster and

shared storage devices participate in the new enhanced quorum model in Windows

Server 2008 R2. Effectively, Windows Server 2008 R2 server clusters have better informa-

tion to determine whether it is appropriate to failover a cluster in the event of a system

or device failure.

The witness-based quorum eliminates the single quorum disk from the cluster operation

validation model. Instead, a completely separate node or file share can be set as the file

share witness. In the case of a GeoCluster where cluster nodes are in completely different

locations, the ability to place the file share in a third site and even enable that file share

to serve as the witness for multiple clusters becomes a benefit for both organizations with

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Windows Server 2008 R2 Technology Primer

distributed data centers and also provides more resiliency in the cluster operations

components.

Stretched Clusters

Windows Server 2008 R2 also introduced the concept of stretched clusters to provide

better server and site server redundancy. Effectively, Microsoft has eliminated the need to

have cluster servers remain on the same subnet, as has been the case in Windows cluster-

ing in the past. Although organizations have used virtual local area networks (VLANs) to

stretch a subnet across multiple locations, this was not always easy to do and, in many

cases, technologically not the right thing to do in IP networking design.

By allowing cluster nodes to reside on different subnets, plus with the addition of a

configurable heartbeat timeout, clusters can now be set up in ways that match an organi-

zation’s disaster failover and recovery strategy.

Improved Support for Storage Area Networks

Windows Server 2008 R2 also has improved its support for storage area networks (SANs)

by providing enhanced mechanisms for connecting to SANs as well as switching between

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SAN nodes. In the past, a connection to a SAN was a static connection, meaning that a

server was connected to a SAN just as if the server was physically connected to a direct

attached storage system. However, the concept of a SAN is that if a SAN fails, the server

should reconnect to a SAN device that is now online. This could not be easily done with

Windows 2003 or prior. SCSI bus resets were required to disconnect a server from one SAN

device to another.

With Windows Server 2008 R2, a server can be associated with a SAN with a persistent reser-

vation to access a specific shared disk; however, in the event that the SAN fails, the server

session can be logically connected to another SAN target system without having to script

device resets that have been complicated and disruptive in disaster recovery scenarios.

Addition of Migration Tools

Beyond the standard migration tools that help administrators migrate from one version of

Active Directory to another, or to perform an in-place upgrade from one version of

Windows to another, Windows Server 2008 R2 has migration tools to help administrators

move entire server roles from one system to another. These new tools provide migration

paths from physical servers to virtual servers, or from virtual servers to physical servers.

Other tools allow for the migration of DHCP configuration and lease information from

one server to another. These tools and the prescriptive guidance help administrators

migrate servers more easily than ever before.

Addition of Migration Tools

39

Operating System Migration Tools

Windows Server 2008 R2 provides tools that help administrators migrate from older

1

versions of the Windows Server operating system to Windows Server 2008 R2. The

supported migration paths are as follows:

.
Windows Server 2003, Windows Server 2003 R2, Windows Server 2008, and

Windows Server 2008 R2—
These operating systems can be migrated to Windows

Server 2008 R2 using the operating system migration tools and guidance documenta-

tion.

.
x86 and x64—
Servers can be migrated from x86 to x64 and from x64 to x64 with

limitations. Because Windows Server 2008 R2 is an x64 operating system only, there

is no in-place upgrade support from x86 to x64, so the upgrade path is a server-to-

server transition, not in-place. However, x64 to x64 in-place is supported as long as

any applications sitting on the server can be upgraded from one x64 platform to the

Windows Server 2008 R2 x64 platform.

.
Full Server and ServerCore—
Operating system migration from Full Server to

ServerCore and from ServerCore to Full Server are supported typically as a server-to-

server migration because in-place migrations between Full Server and ServerCore

have limitations. The GUI needs to be added or removed and, thus, applications are

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typically migrated rather than complete operating system migrations between the

platforms.

.
Physical and virtual—
Virtualization of guest sessions is the de facto standard in

data centers these days and the implementation of applications on virtual guest ses-

sions is the norm. As such, organizations wanting to migrate from physical server

configurations to virtual guest sessions can leverage the migration tools and guid-

ance available in performing server and application migrations to virtual server roles.

Server Role Migrations

Included in Windows Server 2008 R2 are tools and guidance that help administrators

migrate server roles to Windows Server 2008 R2 server systems. The supported migration

paths are as follows:

.
Active Directory Domain Services—
The migration from Active Directory 2003

and Active Directory 2008 to Active Directory 2008 R2 is fully supported and

covered in Chapter 16 of this book.

.
DNS and DHCP migrations—
New migration tools are available that help adminis-

trators migrate their DNS and DHCP servers from running on previous versions of

Windows to servers running Windows Server 2008 R2, and not only just the service

configurations but also DNS and DHCP data. In the past, the migration of DHCP to

a new server usually meant the loss of DHCP lease information. With the new

migration tools in Windows Server 2008 R2, an administrator can now migrate the

server configuration as well as the lease data, including lease expiration data, as part

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CHAPTER 1

Windows Server 2008 R2 Technology Primer

of the migration process. These migration tools are covered in Chapters 10 and 11

of this book.

.
File and print migrations—
Included in the migration tools for Windows Server

2008 R2 are features that migrate file data, included file permissions, and the migra-

tion of print server configurations and settings from older servers to new Windows

Server 2008 R2 configurations. These migration tools help simplify the process of

updating servers from old server systems to new systems with the least amount of

impact on the organization and drastically simplify the process of migration for

domain administrators.

Improvements in Server Roles in Windows Server

2008 R2

The introduction of Windows Server 2008 R2 added new server roles to Windows as well

as enhanced existing roles based on feedback Microsoft received from organizations on

features and function wish lists. Server roles are no longer installed by default on a

Windows Server 2008 R2 server and have to be selected for installation after the initial

installation of the Windows operating system.

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Some of the new or improved server roles in Windows Server 2008 R2 include Internet

Information Services 7.5, SharePoint Services, Rights Management Service, and Windows

virtualization.

Introducing Internet Information Services 7.5

Internet Information Services 7.5 (IIS) is the seventh-generation web server service from

Microsoft. Microsoft completely redesigned IIS 7.0 in Windows Server 2008 rather than

just adding more functions and capabilities to the exact same IIS infrastructure as they

have done for the past several years. The good part of the new IIS 7.x is that it now

provides organizations with the ability to manage multiple web servers from a single

console, rather than having to install components and configure each web server individ-

ually. This requires organizations to rethink and redesign their web management tasks

from pushing the same content to dozens of servers individually to a process where infor-

mation is pushed to a Shared Configuration store, where common information is posted

and shared across all IIS 7.x servers. Organizations can continue to post information the

old way by pushing information individually to each server; however, to gain the advan-

tage of the new IIS 7.x services, redesigning how information gets posted should be

changed to meet the new model.

The advantage of the new model of content posting is that information is stored, edited,

and managed in a single location. At a designated time, the information in the single loca-

tion is posted to each of the servers in the shared application hosting farm. This is a signif-

icant improvement for organizations managing and administering a lot of IIS web servers.

This ensures that all servers in a farm are using the same content, have been updated

simultaneously, and any changes are ensured to be propagated to the servers in the farm.

Web administrators no longer have to worry that they forgot a server to update, or to

Improvements in Server Roles in Windows Server 2008 R2

41

stage an update at a time when each individual server could be updated in a fast enough

sequence that the experience of all users was going to occur at around the same time.

1

IIS 7.5 is covered in detail in Chapter 12, “Internet Information Services.”

Windows SharePoint Services

A significant update provided as part of the Windows Server 2008 client access license

(CAL) is the ability to load and run Windows SharePoint Services. Now in its third genera-

tion, Windows SharePoint Services (WSS) is a document-storage management application

that provides organizations with the capability to better manage, organize, and share

documents, as well as provide teams of users the ability to collaborate on information.

Windows SharePoint Services sets the framework from which the Microsoft Office

SharePoint Services 2007 (MOSS) is built. MOSS leverages the core functionality of WSS

and extends the capability into enterprise environments. WSS is the basis of document

sharing and communications for organizations in the evolution of file and information