Microsoft Windows Server 2003 and Microsoft Windows Storage Server 2003: Meeting the Storage Challenges of Today’s Businesses

Contents

Introduction 2

Microsoft® Windows Server™ 2003 and 3

Microsoft® Windows® Storage Server 2003: Robust Storage Solutions

Storage Challenges 4

The Need for Scalable Solutions 4

The Need for Fault Tolerance 4

The Need for Protected Data 5

The Need for Manageable Solutions 5

The Need to Control Costs 5

Advantages of the Windows 6

Storage Platform

New and Enhanced Storage Solutions 8

VDS for Storage Disk Management 8

VSS for Effective Data Protection 10

FRS for Remote Replication 11

DFS for File Sharing 11

ASR for Rapid Disaster Recovery 12

EFS for Secure Data 12

iSCSI for Storage Area Networking 13

MPIO for Highly Available Data 14

Enhanced Support for SANs 14

Summary 15

Overview of Windows Storage 16

Server 2003

Introduction 16

What is Windows Storage Server 2003? 17

Advantages of Windows Storage 17

Server 2003

The Basics: How NAS Works 19

File Serving Component 19

Hardware Component 19

Storing Component 19

Optimising NAS 19

Windows Storage 20

Server 2003 Features

Networking 20

File Serving 21

Storage 22

NAS Management Software 23

Performance 23

Integrated Snapshots 24

Improved End-User Experience 24

New Features in Windows 25

Storage Server 2003

Volume Shadow Copy Service (VSS) 25

Virtual Disk Service (VDS) 26

Multipath I/O (MPIO) 26

Distributed File System (DFS) 27

NAS Deployment Scenarios 28

File Serving 28

Server Consolidation 28

Local and Remote Site Replication 29

for Business Continuity

NAS-SAN Fusion 29

Summary 30

Related Links 30

Data is a business’s most valuable asset. The rich media

content of static and dynamic Web pages, huge volumes

of email, 24 hours a day, 7 days a week demands of

e-commerce, and the dependence on massive relational

databases have all contributed to the explosion of

mission-critical data. For the system/storage administrator,

managing an organisation’s growing wealth of information has

become an increasingly complex, high-pressure undertaking.

Key to the storage administrator’s success is ensuring that

information is:

Available to those who need it when they need it.

Protected from security risks, system failure or

catastrophic events.

Rapidly recoverable should the need arise.

The system administrator must accomplish these tasks

in the context of rapidly changing storage technologies.

While there are many storage solutions available today,

not all solutions scale well with organisational growth,

nor are all equally capable of delivering cost-effective

high-performance solutions.

The new and enhanced data and storage management

capabilities of Microsoft Windows Server 2003 and

Microsoft Windows Storage Server 2003 are critical tools

in helping system and storage administrators do more with

less. This white paper discusses the storage challenges

that face businesses today and the benefits of using the

Windows Server platform to meet those needs.

Introduction

2

Windows Server 2003, Microsoft’s newest release of the

Windows server operating system, is a multi-purpose server

designed to handle a diverse set of server roles, including

file and print, mail, Web, terminal and directory services. The

integrated storage services in Windows Server 2003 have

been enhanced and expanded to include a number of new

features that help businesses control storage management

costs and increase availability of data. Features such as

the Volume Shadow Copy Service (VSS) and the Virtual Disk

Service (VDS) make it easier to manage and maintain disks,

helping lower Total Cost of Ownership (TCO) especially in

complex multivendor storage environments. Point-in-time

imaging capability through VSS simplifies and speeds up both

backups and restores. And, the Shadow Copies for Shared

Folders feature of VSS enables end users to restore their own

files and folders without IT intervention. High availability is

enabled through multi-pathing and clustering.

Windows Storage Server 2003 is a Network Attached Storage

(NAS) operating system, built upon the Windows Server 2003

operating system. Windows Storage Server 2003 lets Original

Equipment Manufacturers (OEMs) build appliances optimised

for file serving, since applications unnecessary to the file

serving and storage tasks are not activated. Storage Server

NAS devices are headless (without monitor, keyboard or

mouse) and can be managed through a Web-based user

interface. Designed for ease of deployment and seamless

integration into the existing network, Windows Storage

Server 2003 can provide expanded storage capacity to users

on the network in under 15 minutes. The Storage Server NAS

solution is especially appropriate for organisations that do not

wish to put extensive IT resources into setting up multiple file

servers and managing them.

Windows Server 2003 and Windows Storage Server 2003: Robust Storage Solutions The storage administrator in all businesses, large or small, is

faced with a number of key problems:

Ensuring that as an organisation’s data grows, storage

capacity scales to accommodate it.

Ensuring that mission-critical data is well protected from

the risk of hardware failure, security breeches, or disaster;

and that data is available on an on-demand basis.

The sections that follow explore these needs in greater detail.

The Need for Scalable Solutions

Embedded hard drives or directly attached external disks

– referred to as DAS (Directly Attached Storage) – is the

most common way to store data on desktops, workstations

and servers. The simplest solution to the demand for more

storage capacity is to add more hard drives, upgrade to higher

capacity disks, or to purchase additional computers each

with more DAS. While DAS solutions can be effective for many

businesses, they are often only temporary fixes, and result in

a number of challenges for the storage administrator.

Decentralised Data

As the number of DAS systems grows, increasingly, data is

dispersed throughout the company, making it difficult for

users to know what resources exist and where to find them.

This is an especially troublesome problem with data stored

on desktops since, unless individuals allow file sharing, there

is no simple means of making the data accessible to others.

Even with sharing enabled, there is no effective mechanism

to determine exactly where information is stored, or which

document is the most up-to-date version.

Migration of a company’s critical data to a centralised server

helps the situation somewhat since the data can be shared

readily across the network. But as more servers are added to

increase storage capacity (and to provide redundancy in the

event of hardware failure), without a mechanism to unify the

presentation of directories and file shares, users still have the

problem of not being able to find the data that they need – or,

in some cases, even knowing that it exists.

Underutilisation of Storage Resources

Only the computer to which the storage is attached can

access DAS. Effective storage planning requires accurate

predictions about which users and applications will

require more storage capacity, and those resources must

be provisioned before disk capacity is exceeded.

Unfortunately, DAS always scales poorly over the long term.

Some computers inevitably exceed their storage capacity,

while others have excess capacity but no means to share

those resources effectively.

Adding more servers does not eliminate the problem of

inefficient utilisation of storage space between servers.

Storage remains local to each server; thus space may be

available on one server but capacity exceeded on another.

Anticipating growth and implementing storage solutions that

scale with growth remains a problem.

Proliferation of Storage Equipment

Adding servers to meet the need for greater storage capacity

is an effective solution as long as the number of servers

an administrator can handle remains manageable. Servers

must be maintained, backed up and serviced, all of which

rapidly becomes a management headache for the system

administrator. And as long as storage remains attached

directly to the server, each server must have its own directly

attached tape drive for backups; a very costly solution for

equipment that is only in use during the backup and

restore process.

Ensuring Compatibility with Storage Networking

Solutions

The best storage solutions not only meet today’s storage

needs, they also scale well with more advanced storage

solutions, such as Network Attached Storage (NAS) and

Storage Area Networks (SANs).

The Need for Fault Tolerance

More and more businesses rely on making their services

and information available for access 24 hours a day,

7 days a week. Failure in any of a number of hardware

components – storage devices, storage interconnects,

cabling, network interconnects, processors, motherboards

and power supplies – can result in a temporary or permanent

loss of data. Fault tolerance can be achieved through

redundancy of hardware components, and is one means

by which to ensure highly available data.

Storage Challenges

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Redundant Disks

Externally attached storage devices can be made highly

redundant using RAID (Redundant Array of Inexpensive Disks)

subsystems. Redundancy can be achieved in a number of

different ways, including mirroring, which replicates the data

on one disk to one or more additional disks. Should one

disk fail, the system can “failover” to a second disk with the

replicated data.

Redundant Hardware through Clustering

A cluster is two or more computer systems that act and are

managed as one. Clustering allows applications to remain

online, even if a server goes down. Users are redirected to

another computer without any loss of services.

The Need for Protected Data

System administrators must protect data not only from

hardware failure, but also from data corruption, user error

and disasters. The most common means of protecting data

from these problems is through tape backups and restores.

Unfortunately, this solution provides only partial protection.

Poor Protection of Desktops and Laptops

The individual user must back up DAS. However, users are

rarely effective in performing regular backups, and for that

reason, system administrators strongly advocate storing

documents and data that is critical to the company on the

server, where it can be backed up properly.

Open File Backup Constraints

While management of backups can be simplified using a

centralised backup server, the time required to perform

backups conflicts with the demand for continuously available

data. Trying to back up an open file can result in data

corruption. As a consequence, those files must either be

skipped (meaning that the backup is incomplete) or users

must close their applications during backups. Preventing

data corruption during the backup process has meant that

the backup period must be restricted to when users are not

trying to access their files across the network – typically, just

evenings and weekends. As organisations produce more

and more data that must be backed up, the time it takes to

backup data can exceed the nightly or even weekend

backup times.

The Need for Manageable Solutions

System administration can become enormously complex,

especially in mid-sized and large organisations. Administrators

are responsible for managing Web, application and database

servers and for clustering those servers to ensure effective

performance and high availability. They are also responsible

for managing dedicated Storage Networks (SANs) that host

multivendor storage devices, each with a vendor-specific disk

management application. These management consoles are

not standardised, making training and usage unnecessarily

complex. Administrators are responsible for managing

utilities for such tasks as backup, data mining and testing.

Since applications are not storage-aware, managing data

for backup and transport can be a complex and inefficient

process. Finally, although many organisations require multiple

platforms to support various applications, there are increasing

demands that data be shared among users irrespective of

whether they use Windows, UNIX or some other

operating system.

The Need to Control Costs

Organisations are demanding that system administrators

deliver robust, reliable and scalable storage solutions within

a budget that remains flat or has declined. Among the most

effective ways to control costs and still deliver effective

storage solutions is to consolidate resources. NAS solutions

provide a cost-effective means to add storage capacity

while consolidating equipment. As many as 10 and up to 25

file servers can be consolidated into a single NAS device,

depending on the amount of data consolidated. Not only does

this mean that equipment and licensing costs are curtailed, it

also enables the consolidation of related equipment such as

backup devices and the reduction in management overhead.

Solutions that automate or speed up storage provisioning,

backups and general maintenance all decrease the need for

administrator interventions, saving the administrator time and

effort. These costs can be directly passed on to the business,

lowering total cost of ownership and ensuring the most

effective utilisation of existing storage resources.

Both Windows Server 2003 and Windows Storage Server

2003 provide businesses with reliable storage solutions

that are designed to keep data protected, highly available,

and easily managed – without huge capital expenditures.

Windows Server 2003 and Windows Storage Server 2003

help businesses to reduce their total cost of ownership by:

Lowering IT Intervention Costs.

The accidental deletion or overwriting of files has long

been the bane of system administrators charged with the

time-intensive and costly task of locating and restoring

single files from tape. The Shadow Copy for Shared Folders

(SCSF) feature of the new Volume Shadow Copy Service

(VSS) enables users to easily restore their own deleted

files, without IT intervention.

Managing Backups and Restores More Effectively.

As organisations produce more information, backing up

data becomes an increasingly time-intensive and potentially

disruptive operation. Tape backups have the additional

drawback that it is only during the restore process that

data corruption becomes apparent – making data recovery

impossible. With the new VSS, open file backups are enabled,

thus making unnecessary the disruptive practice of shutting

down applications during backup to prevent data consistency

issues. The process of creating Shadow Copies is designed

to ensure data integrity prior to the tape backup process,

thus ensuring that the data is complete, uncorrupted and

able to be restored.

In the case of catastrophic system failures – cases where

the hard drive loses all operating system information and

is effectively stripped down to the bare metal – Automated

System Recovery (ASR) makes possible rapid restore of the

system’s original state possible.

Increasing Availability and Security of Data.

Making data highly available throughout an organisation

requires data redundancy. The VSS allows administrators

to schedule making regular copies of data stored on disk,

and makes it painless for users to access consistent

point-in-time copies of data. Moreover, since only the

changes to the data are saved1, Shadow Copies take up

very little disk space, enabling companies to make copies

of whatever data is needed.

The File Replication Service (FRS) controls replication

and synchronisation of data. This data can be made

highly available to remote sites using the Distributed

File System (DFS).

Managing Multi-Vendor Storage More Effectively.

Multi-vendor storage device management has required

that the system administrator manage each device

independently – and use a different vendor supplied

interface to do so, thus adding another layer of complexity

to the system administrator’s job. With the introduction

of the new Virtual Disk Service (VDS), the system

administrator can use a single interface to configure

storage from multiple vendors. (This solution is fully

implemented in partnership with the storage

hardware vendors)2.

Increasing the Effectiveness of File Sharing.

The Distributed File System helps to make the end user’s

process of locating and accessing files distributed across

an organisation effortless. With the Windows Server 2003

release, DFS has been enhanced to allow for multiple DFS

root directories on each server. This capability means that

it is no longer necessary to add an additional server for

each additional DFS root directory. DFS also offers closest

site selection, ensuring access to the nearest available

copy of the data at the lowest cost.

Advantages of the Windows Storage Platform

1 This is true when using shadow copy capabilities through the operating system. Hardware provider solutions may be different.

2 Hardware vendors create the hardware provider (the component that controls the storage device), and use the VDS application programming interfaces (APIs) to provide hardware-specific VDS functionality.

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Leveraging Existing Network Infrastructure for SAN

Storage. Windows support for iSCSI technology allows

users to connect computers to consolidated storage

devices using existing Ethernet technologies, rather

than having to install a separate Fibre Channel network.

Microsoft’s enabling of this technology will help bring the

advantages of SAN to mid-sized and small businesses

that otherwise could not afford the extra cost and

management of running a separate Fibre Channel network.

SAN technology based on IP also removes the physical

limitations of moving data further than the current 10km

limit imposed by Fibre Channel technology.

In addition to enabling less expensive SAN solutions, the

Windows storage platform now provides better support for

SANs. Administrators can now control volume mounting to

protect volumes from unintentional access. Handling of Fibre

Channel SANs has been improved, as has SAN Host Bus

Adapter (HBA) interoperability, both of which further ease

administration complexities. Lastly, boot from SAN, with

vendor support, is greatly enhanced in Windows Server 2003.

Windows Server 2003 and Windows Storage Server 2003 give

businesses cost-effective, highly manageable and scalable

storage solutions, designed to meet a range of business

needs and helping to ensure that the cost of managing

storage does not exceed storage capital expenditures.

The next section details the new storage features and

enhancements to existing functionality.

The key to reliable storage solutions lies jointly with managing

disks and data effectively. Windows Server 2003 and

Windows Storage Server 2003 provide a number of services

and tools that the system administrator can use to manage

both data and storage effectively, thereby maximally exploiting

a company’s storage investments.

VDS for Storage Disk ManagementVirtual Disk Service (VDS) is new to Windows Server 2003

and Windows Storage Server 2003.

VDS enables storage solutions that are:

New and Enhanced Storage Solutions

VDS is the foundation supporting the Disk Management

User Interface (UI) and a number of scriptable Command

Line Interfaces (CLI) for disk management. VDS enables disk

management of DAS, NAS and SAN devices, and is especially

helpful in simplifying system administration of multi-vendor

storage devices on SANs.

Disks can be housed singly (as is the case with embedded

disks) or grouped together in large storage subsystems. The

disks within a storage subsystem can be configured as:

JBOD systems

JBOD systems are “Just A Bunch Of Disks.” Early disk

management software could format, partition and assign

drive letters to each disk individually. However, prior to

technologies like VDS, there was no means by which to

manage these disks as a unit.

RAID systems

Not only are these disks housed together physically but

also, with the appropriate disk management software, these

disks can be variously configured such that virtual disks

are created across multiple physical disks. So configured,

each virtual disk acts as a single logical unit, numbered for

identification (hence they are referred to as LUNs). Each RAID

type (most commonly RAID 0-5) is associated with a particular

level of data redundancy, which translates into enhanced

performance and data protection. RAID devices can be further

distinguished by where the RAID controller software lies:

Software RAID. The intelligence for creating the RAID

types lies in the host operating system. All processing

control resides in the OS.

Hardware RAID. Control for configuring RAID types does

not lie within the host OS, but is either on an internal RAID

adapter card or it is external to the host computer system,

residing on the external disk subsystem itself.

DISKPART

DISKPART is a scriptable CLI, which provides the commands

for managing the creation, extension and deletion of

partitions on both basic and dynamic (expandable) disks.

The utility can be used to configure both simple volumes

(which span a single partition) and multi-partition volumes

(which can span multiple partitions on a single disk or on

multiple disks). Multi-partition volumes can be configured to

provide different levels (RAID types) of data redundancy for

data protection and performance improvements. Software

RAID devices are controlled by DISKPART.

Scalable Configures storage devices on NAS and SAN

Fault tolerant Configures RAID (mirroring, striping or striping with parity) for data redundancy

Manageable

Provides a single interface for multi-vendor storage3

Controlled mount points for SANs

3 Where supported by hardware providers.

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Volume extension is particularly important in those instances

when a volume has nearly reached allocated capacity but

there is still free unallocated disk space available on a single

disk or RAID array. Volume extension allows for an increase

in the size of the volume, with no loss of data.

DISKRAID

DISKRAID is a scriptable CLI available through the

Windows Server 2003 Resource Kit or the Deployment Kit.

It is used with VDS and vendor-specific hardware providers

to configure virtual disks (logical disks that span two or

more physical disks) on hardware RAID devices.

Multi-Vendor Disk Management

Multi-vendor disk management on SAN systems has, until

now, been a complex undertaking. Configuration of storage

devices on the SAN has previously been through vendor-

specific management applications. These applications are

not standardised, and require that storage administrators be

trained on how to use differing interfaces. VDS overcomes

this lack of standardisation by providing a single standardised

interface by which to manage multi-vendor storage devices.

VSS for Effective Data ProtectionVolume Shadow Copy Service (VSS) is new to

Windows Server 2003 and Windows Storage Server 2003.

VSS enables effective:

The VDS scriptable command line interfaces allow

administrators to automate storage operations across

storage systems from multiple vendors. Using the CLI, the

administrator can create a script to add storage to the

network. Although this script works with multi-vendor storage

hardware, no vendor-specific training is necessary to create

the script. When new drives are added to the storage array,

the administrator can run the script that automatically

configures the disks for use. VDS multi-vendor disk

management requires a “hardware provider” – software from

the vendor that translates VDS abstractions into hardware

RAID specific instructions for configuring RAID sets.

The VSS provides the infrastructure for creating high

consistency point-in-time copies of single or multiple volumes.

The service provides effective data protection to both system

administrators and end users.

Open File Backup

VSS coordinates with business applications, backup

applications and storage hardware to provide application-

aware data management. Previously, there had been no

means by which backup applications could prepare data for

backup – applications either had to be shut down to prevent

data corruption or files were simply not backed up. Now, with

VSS, open file backups are possible and application users do

not have to worry about closing files or being unable to use

their applications.

Data Integrity

With VSS, the storage administrator no longer has to worry

about missing data during the backup process, or about the

possibility of undetected data inconsistencies. If there is a

problem during shadow copy creation, the administrator is

notified immediately of an inconsistency between the original

data and the shadow copy. This enables the administrator

to reschedule shadow copy creation before committing the

backup copy to tape, rather than discovering during the

restore process that the backup had been unsuccessful.

User-Enabled File and Folder Restores

Shadow Copies for Shared Folders (SCSF) allows end users

to use the “Previous Versions” UI to restore deleted or

overwritten files (or whole folders of files) without the need

for system administrator intervention. The process of creating

Shadow Copies does not affect the way that users work, since

the process is transparent to users. However, should a file be

deleted or overwritten, the user is empowered to manage their

own files, recovering lost data and fixing mistakes without

having to rebuild the file or wait for IT to restore it from tape.

Restored files retain the permissions and file preferences

associated with the original files. Moreover, since SCSF

works with any type of file built with any application, all

users can benefit.

Data Transport

Using third-party software, shadow copies can be made

available to other servers that share a common storage pool.

Transport of data among systems is virtual, and is done

through the process of LUN masking and unmasking, under

VDS control. Virtual transport of data enables servers to share

data for more effective backups, data mining and testing.

Data Protection

User-enabled Shadow Copies for Shared Folder (SCFC) file restores

Open-file backups

System

Management

With third-party support, shadow copies can be transported to other systems for backups, data mining or testing

Faster backups

Faster restores

Cost Control Fewer staffing resources needed

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The FRS is used to copy and maintain files and shared

folders on multiple servers simultaneously. When changes

occur, local site content is synchronised immediately; remote

site content is changed according to an administrator set

schedule. FRS, in conjunction with DFS, makes data highly

available, even to remote sites.

It is important to note that FRS is not an effective means

of providing data protection from software bugs, viruses or

other causes of data corruption, since the corrupted data is

replicated to failover disks as well.

DFS for File SharingDistributed File Sharing (DFS) is enhanced in

Windows Server 2003 and Windows Storage Server 2003.

DFS enables storage solutions that are:

DFS simplifies locating and managing data multiple network

servers. This is especially important to users who must get

access to widely distributed data on different servers, but

do not want to be hampered with having to remember and

provide the server address that data lies on in order to

access it.

Unified Namespace

The DFS enables end users to readily find data housed

on different disks by presenting a single view of physical

storage, as if the data were only on a single machine. The

system administrator accomplishes this by set up a single

unified system of naming (the “namespace”) such that users

FRS for Remote Replication File Replication Service (FRS) is enhanced in

Windows Server 2003 and Windows Storage Server 2003.

FRS enables:

Highly Available Data Failover to replicated disk in the event of hardware failure

Scalable

Enables consolidation of distributed shared folders into a single namespace

Simple integration of new servers and storage into namespace

Manageable Users can readily locate and share data

Fault tolerant Microsoft® Active Directory® information is used to provide failover to alternate site

Highly Available Load balancing helps keep user files highly available

Cost-effective Failover to least expensive alternate site

can share and access files, whether they are on the same

machine, in different departments, or at branches of an

organisation across a country.

Simple Migration

As organisations move existing data to newer, more powerful

servers, the namespace organisation remains the same,

without requiring additional user education.

DFS has been enhanced by directing clients to the closest

available DFS server, rather than having them accessing a

distant share if one is available nearby or even locally. Not

only does this help businesses control costs, it also ensures

the best network performance for each client.

While backing up data to tape protects mission-critical data

from catastrophic events such as fire or massive electrical

surges, it does nothing to protect system software stored on

the hard drive, since that information is not copied during the

backup process. A critically damaged hard drive will lose all

critical registry information, system files, and disk partition

information; nothing remains but the bare metal. Restoring

the base operating system plus the backup application (the

minimum required to restore backed up applications and

data) is a time-intensive process.

With ASR, the system administrator prepares for such a

disaster by saving to floppy disk a complete backup set of

information about how the server was configured, including

any volume information. In the event of system failure, this

backup set is used with the ASR restore CD (which contains

the necessary software and drivers to allow the restore) to

rapidly restore all system setup information.

ASR is also useful when upgrading to a more powerful server,

since it eases the process of migrating system information

from the old server to the new.

ASR for Rapid Disaster Recovery Automated System Recovery (ASR) is new to

Windows Server 2003 and Windows Storage Server 2003.

ASR enables effective:

Disaster Recovery Allows complete recovery of OS and system settings

EFS encrypts data as it is stored to disk, preventing it from

being accessed or read by users who lack the appropriate

authorisation. The user may enable encryption without any

administrative intervention. Backup copies of encrypted files

are also encrypted. To encrypt data traveling over the network,

Internet Protocol security (IPsec) is also available. Encryption

is especially useful for mobile units that are highly vulnerable

to theft.

EFS has been enhanced to prevent the removal and mounting

of storage volumes onto a different system. In Windows

2000, because encryption had been enforced at the file and

directory level, security protection could be bypassed.

In Windows Server 2003 and Windows Storage Server 2003,

the data itself is encoded, preventing such security breeches.

Administrators can authorise additional users to access

encrypted files, as well as enable users to encrypt Web

folders, thus provide a simple and highly secure method

for users to share folders.

EFS for Secure Data Encrypted File System (EFS) is enhanced in

Windows Server 2003 and Windows Storage Server 2003.

EFS enables effective:

Data Protection Data protected even on mobile units

1211

Conventional networking technology enables network file

transfer. However, for some applications (such as databases),

it is more effective to transfer data to storage in its more

granular form of blocks rather than files. While parallel SCSI

interconnects enable transfer of block level data, both the

number of storage devices that can connect to a computer,

and the distance those devices can be from the computer,

are highly restricted. Fibre Channel (FC) uses the serial SCSI

protocol that enables block transport, and FC interconnects

facilitate the attachment of many devices over long distances

(10km at 1Gbs in standard implementations). Both these

factors have combined to make FC the dominant technology

for SAN solutions.

The following are disadvantages of FC:

The infrastructure (wiring, interconnects, switches and so

on) tends to run on proprietary firmware.

Specialised training (which is difficult to obtain) is

necessary for effective SAN management.

FC imposes a 10km distance limitation on data transfer;

iSCSI, on the other hand, enables data transfers over WAN

distances.

The development of iSCSI – block-based storage over

IP networks – is a technological breakthrough that can

leverage a company’s existing infrastructure to provide a

SAN solution. Microsoft’s iSCSI initiator enables computers

to access storage on the network, to determine if the storage

is available for use, and to transport data securely over the

Internet to the storage device. Microsoft’s iSCSI initiator,

available for free and downloadable from the Internet,

helps bring high-end solutions – like SAN – to mid- and

small-sized businesses.

iSCSI for Storage Area Networking Internet SCSI (iSCSI) is new to Windows Server 2003 and

Windows Storage Server 2003.

iSCSI provides storage solutions that are:

Scalable Enables block-based (SAN) storage on existing IP networks

Manageable Leverages existing networking technologies

Cost-effective

Dedicated Fibre Channel (FC) equipment unnecessary

No specialised training required

MPIO for Highly Available Data Multipath Input/Output (MPIO) is new to

Windows Server 2003 and Windows Storage Server 2003.

Multipath I/O provides:

MPIO, multipathing or redundant paths for I/O channels,

provides an alternative connection to the storage devices

in case of failure of the primary I/O path. Optimally, MPIO

can provide multiple paths (up to 32) to stored data in

order to improve performance through load balancing.

Path redundancy has long been critical to enterprise

scale organisations.

Microsoft’s MPIO solution is only available though the Driver

Development Kit (DDK), which allows storage vendors to

create interoperable multipathing solutions in their hardware

products. System administrators and end users benefit from

using these products, since they help ensure that end users

have highly available data even in the event of a failure of a

component in the path between the client and storage.

Users can also benefit from increased performance.

Enhanced Support for SANsWith the appropriate interconnect technology (iSCSI or FC),

deploying a SAN in a Windows environment is much simpler

using Windows Server 2003 operating system than it had

been for previous versions of Windows.

Ability to boot from the SAN. Previous versions of the

Windows platform required that the boot operation be

conducted using the storage attached to the main server.

If that server failed, however, another server had to reboot

the system, which could be a time-consuming and difficult

process. In combination with SAN vendor support,

the Windows Server 2003 operating system enables

the system administrator to reboot across the SAN,

thus reducing downtime.

Flexible Volume Mounting. In the past, in the shared

disk environment of SANs, if Windows was able to detect

a virtual disk, it would attempt to claim it for its own,

failing to recognise another system’s prior ownership.

This limitation could result in loss of data. By controlling

mount points, Windows is prevented from accessing

volumes that are not assigned to the OS.

Highly Available Data Failover to an alternative path in case of path failure

Fault Tolerance Redundant hardware enables failover

1413

Companies of all sizes are searching for cost-effective

solutions to their storage management challenges. Many of

the high-end storage solutions – including the consolidated

storage network model itself – were first worked out to solve

the business problems of large companies. These storage

customers have demanded the most advanced technologies

available to solve their storage problems, and have driven the

development of many technological innovations.

Windows Server 2003 and Windows Storage Server 2003,

together with Microsoft’s OEM and Independent Software

Vendor partners, deliver advanced storage management

solutions to a diversity of companies. Snapshots and remote

replication capabilities are no longer the exclusive tool set of

high-end (and high-priced) storage solutions. These powerful

capabilities are built into Windows Server 2003 and

Windows Storage Server 2003, making advanced storage

solutions available to mid-sized and even small organisations.

Microsoft also provides advanced storage solutions to

enterprise organisations. For many years, large companies

had been locked into using a single hardware or software

provider for all of their storage needs, regardless of the

fact that not all needs required enterprise-level solutions.

As greater interoperability becomes part of the storage

standard, lower-cost options from multiple vendor sources

are possible. Microsoft’s robust storage platforms provide

one such option.

SummaryIntroductionDevelopment of technologies delivering storage over the

network has revolutionised the availability, distribution and

accessibility of storage resources. Attaching storage directly

to the company network helps to eliminate or reduce the

drawbacks that businesses experience when using DAS.

These drawbacks include:

Limited storage capacity and scaling constraints as data

assets grow.

Proliferation of computer hardware and software to meet

increased storage capacity needs.

Proliferation of hardware and software necessary to protect

the data allocated to new storage.

Increased management complexity for the system

administrator(s) configuring and maintaining IT client and

server systems.

Poor or inconsistent protection of data on client desktops

and laptops.

Limited or laborious access to data, especially between

company workgroups, departments and branches.

Temporary or permanent loss of data resulting from

hardware failures, data corruption or user error.

Spiralling costs associated with capital expenditure,

increased staffing, and production downtime resulting from

data loss.

Network Attached Storage (NAS) is one solution to these

challenges. NAS storage and file-serving devices can be

attached directly to the company intranet. Storage directly

attached to the network becomes accessible to all computers

that can access the network. NAS servers are designed

for ease of deployment: they can be plugged directly into

the network without disruption of services, management is

minimal and simplified, and they are largely maintenance

free. NAS devices are an ideal means by which to consolidate

file servers and backup equipment and to expand

storage capacity.

A second networked storage solution is the installation of a

SAN. Unlike NAS solutions, these dedicated storage networks

require considerably more planning to deploy, and their

management is more complex. SAN solutions are ideal for

database and online processing applications requiring rapid

data access, but because SAN storage devices serve block-

level data rather than files, the installation of a Fibre Channel

(FC) network to transport the SCSI (Small Computer System

Interface) commands is necessary4.

A third storage network solution is a hybrid one: NAS devices

can be attached to SANs. In this configuration, the NAS

components necessary for filing are physically separated

from the components necessary for storing: a NAS “head” or

“gateway” (containing the filing functionality) attaches to the

LAN network, and behind that lies the storage component

– a SAN consisting of the FC network (wiring and switches)

and the storage disks.

Overview of Windows Storage Server 2003

1615

4 Microsoft, with its iSCSI initiator software released in June 2003, is enabling block transport over company intranets. See the Enterprise Storage Division white paper, “Microsoft Support for iSCSI” for details.

5 Any system designed to run an operating system.

What is Windows Storage Server 2003? Microsoft Windows Storage Server 2003 is a Network

Attached Storage (NAS) operating system that enables

OEMs to build appliances that provide dedicated file

serving capabilities and storage on the network. Windows

Storage Server 2003 is built on top of Microsoft Windows

Server 2003, which ensures that NAS devices built upon

the Windows Storage Server operating system have all

the performance and scalability benefits associated with

Windows Server 2003.

A NAS appliance built Windows Storage Server 2003 is

designed to perform without requiring a monitor, keyboard

and mouse. Instead, this “headless” appliance is managed

remotely through a Web-based user interface for the minimal

configuration tasks required for setup. Unlike application

servers that require proper planning to implement well, NAS

devices built with Windows Storage Server 2003 are designed

to be deployed in under 15 minutes, and can be attached

directly to the company Local Area Network (LAN) with no

interruption to services. Once plugged in, these NAS devices

require minimal maintenance.

Unlike proprietary solutions, Windows Storage Server 2003

works with standard hardware5 from multiple OEMs. This

gives businesses maximum flexibility in choosing among

vendors with the hardware solution that best meets

their needs.

Advantages of Windows Storage Server 2003Windows Storage Server 2003 is designed for simplicity,

reliability and performance. NAS appliances built on Windows

Storage Server operating system integrate seamlessly into

the IT network to provide one of the most economical file

serving and NAS solutions available to departmental and

enterprise-sized businesses.

Ease of Deployment. Depending on the expertise of the

system administrator and the complexity of the computing

environment, installation of an application or general

purpose server can take anywhere from several hours to

a day or more of work. Because Windows Storage Server

2003 comes preconfigured, other than using the Web

browser interface to set up users and shares, the only

installation work necessary is plugging the device into the

company LAN. In under 15 minutes, gigabytes to terabytes

of storage can be made available to users across multiple

OS platforms.

Simple Management. Windows Storage Server 2003 can

be managed remotely though Terminal Services sessions

or through a Web browser interface from any desktop on

the network. Because Windows Storage Server 2003 uses

the Windows operating system, administrators already

familiar with Windows do not have to learn a new NAS

operating system.

Dependability. Windows Storage Server 2003 is designed

to fully support redundant hardware components – disks,

power supplies and fans – to provide continuous and

uninterrupted availability should a hardware failure occur.

And because NAS devices are designed this way, the

potential points of hardware failure are fewer than with

general-purpose servers.

Enhanced Data Protection. Through built-in point-in-

time shadow technology, Windows Storage Server

2003 helps businesses keep their data online 24 hours

a day, 7 days a week. Using the infrastructure provided by

Windows Server 2003 VSS, the system administrator can

use point-in-time shadow copy technologies to make up to

512 snapshots per volume using NTBACKUP (of which

64 are reserved for Shadow Copies for Shared Folders).

These Shadow Copy backups are available for rapid

restores should the need arise. Unlike tape backups,

which can take hours to restore, these Shadow Copy

backups can be restored in minutes.

The end user can also benefit from point-in-time imaging

technologies, using the Shadow Copies for Shared Folders

(SCSF) feature. SCSF enables users to restore accidentally

deleted or overwritten files or entire folders without the need

for IT intervention. A maximum of 64 SCSF per volume

can be created.

ISV Utility Support. NAS devices developed with

Windows Storage Server 2003 include all of the benefits

of application support available in Windows Server 2003.

Critical ISV utilities, such as antivirus, backup, replication

and disk quota software, are immediately available and

supported in Windows Storage Server 2003. NAS devices

not based on Windows Storage Server 2003 are not able to

support these kinds of products without special versions,

or those operational procedures must be performed from

application servers on the NAS files and file.

Robust Security. Because it can be integrated seamlessly

with Microsoft® Active Directory® services, Windows

Storage Server 2003 can take advantage of the Windows

security features such as data and file encryption, network

authentication, secure network transport, and network-

wide group policies.

Load Balancing and Server Failover. Windows Storage

Server 2003 integrates effectively with the Distributed

File System (DFS), enabling effective management of the

servers and files on the business network. DFS works to

provide a single hierarchical view of all the servers and

their shares. Replicating the data across multiple servers

and keeping the data synchronised with File Replication

Service (FRS) is an effective way to balance the network

load. In the event that a server fails, DFS will automatically

redirect clients to the closest available server.

1817

This section provides a brief introduction to how the NAS

server works, and is included to help provide the context for

many of the NAS features available with Windows Storage

Server 2003. Like all NAS servers, Windows Storage

Server 2003 functionally and architecturally consists of

three components: the filing system, the wiring (and related

hardware), and the storage (disk6). These components

together provide the functionality necessary to fulfil

client system application requests for data stored on

the NAS device.

Application requests to read or write data are initiated by

the client system, and can be directed to the storage local to

the client (embedded or DAS), or can be redirected over the

network to the NAS device using network transport protocols.

These I/O requests are then processed by the NAS operating

system before being passed to the disk devices for storage.

File-Serving ComponentThe process of storing and retrieving the data requested by

user applications is known as file serving. File serving is under

control of the operating system software.

1. Application I/O requests (to read or write data) flow from

client-side applications over the LAN to the NAS operating

system (kernel), which queues and schedules the various

client application requests. These requests then pass

to the file system and the volume manager of the

operating system.

2. The file system portion of the operating system controls

security and determines whether or not a file can be

created, opened, written to. The file system also ensures

that the file is addressed to the correct storage destination.

The I/O request then passes from the file system through

the Volume Shadow Copy Service layer (where it may or

may not be processed) volume manager.

3. The volume manager portion of the operating system

readies the data for the specific device(s) it will be

passed onto for storage7. The Virtual Disk Service

(see later section in this paper) is a component of the

volume manager (but not a component of I/O requests).

Hardware ComponentHaving passed out of the operating system, the I/O request

travels over the host bus to the host I/O controller, which is

responsible for correctly addressing the appropriate storage

device and correctly transferring the I/O request commands

and data across the storage I/O bus to the storage device.

Storing ComponentHaving passed into the storage device, the application request

(data) is stored on the appropriate physical or logical disk, as

directed by the file system.

Optimising NASVendors can configure NAS hardware (and firmware8) such

that it is optimised for network file I/O processing and storage.

These components include the NAS processor, memory and

caching, and the storage devices. There are many different

ways to optimise file serving, and the particular approaches

taken are vendor-specific.

The next section describes the networking, file serving and

storage features in Windows Storage Server 2003 that drive

these capabilities.

The Basics: How NAS Works

6 Disks can be both physical and logical (virtual).

7 It is at this step that the data associated with the application request is converted from file format into the constituent granular blocks that are written to storage devices.

8 Software on the vendor hardware; not part of the OS.

This section highlights the networking, file serving and storing

capabilities of Windows Storage Server 2003. This section

provides feature highlights. For a summary of the major

advances in Windows Storage Server 2003, see

“Key Improvements Since Windows Powered NAS 2.0”.

Networking Network Data Transmission Protocols

In order for clients to access storage on the NAS device, they

must be connected to the LAN and network transport must be

enabled. Clients most commonly connect to the NAS server

over Ethernet cabling using the TCP/IP protocol. Depending

on the system platform, other protocol layers may also be

necessary for network transport. Windows Storage Server

Windows Storage Server 2003 Features 2003 provides support for network protocols used by not only

Windows systems, but also by UNIX and Apple systems (see

Table 1), enabling networking across multiple platforms.

Network Security

Windows Storage Server 2003 uses the authentication

services of Windows Server 2003 to ensure that only those

users with permission to access data can do so. An additional

layer of protection is available through the data encryption

capabilities of the Windows operating system (See Table 2).

The NAS Windows Storage Server is able to support security

features for UNIX and Macintosh environments, as well as

earlier Windows platforms.

Network Protocols Additional Information

TCP/IP Used to connect hosts to the Internet.

AppleTalk Networking protocol for Apple computers.

IPX Internet packet exchange. (Administration through Remote Desktop.)

NetBEUI NetBIOS Extended User Interface, used for Windows environments.

SNMP Simple Network Management Protocol, Internet standard for network management.

Telnet Provides remote terminal access to host.

Fibre Channel Transmits block-level data; most common in SAN configurations.

Ethernet Physical network, transmits files; most common transport for NAS.

Table 1. Networking Protocols Supported by Windows Storage Server 2003

Security and Authentication Additional Information

Kerberos Network authentication protocol for client server configurations.

SSL Secure Socket Layer protocol, provides connection security for Web servers.

IPsec Internet Protocol Security, provides encryption for network transmission.

Active Directory Directory service for Windows OS, acts as central authority for network security.

Windows NT® DomainAdministration (including security and authentication) of users, groups, servers and so on in Windows NT environments.

NTLM Windows NT LAN Manager provides security for connections between NT clients and servers.

NIS Network Information System (for UNIX servers).

Apple UAM User Authentication Module.

Table 2. Security and Authentication Support in Windows Storage Server 2003.

2019

File ServingFile Sharing Protocols

File serving, as discussed earlier, is the process of opening,

closing, reading and writing files. In order for file serving to

be enabled over the network, file-sharing protocols must be

supported. These protocols enable clients to make requests

and receive responses from remote devices, such as a NAS

storage box.

Many NAS devices enable only simple file processing

because they include support only for the standard file

systems: the Common Internet File System (CIFS) and

Network File System (NFS). In contrast, Windows Storage

Server 2003, with its support for multiple file sharing

protocols (Table 3), allows for complex multi-platform file

processing. In addition to Windows clients, Windows Storage

Server 2003 supports file processing for UNIX, Macintosh,

and Web HTTP clients, among others.

Supported Utilities and Applications

Although one of the advantages of NAS is that it is a

dedicated file server and not overburdened with applications,

the data on the server nevertheless requires protection

from data corruption, and the possibility of hardware failure.

Because it is based on the Windows Server 2003 operating

system, Windows Storage Server 2003 is able to support

anti-virus and backup utilities (see table 4). In addition,

Windows Storage Server 2003 integrates seamlessly with

critical Windows features, such as DFS and FRS.

Protocols Additional Information

SMB/CIFS Enables Windows system-based file sharing.

NFS Enables UNIX/Linux-based file sharing. NFS 3.0 supported in Windows Storage Server 2003.

AppleTalk Enables Apple file sharing.

HTTP Enables Web file sharing.

WebDAV Enables desktop users to manage Web-based files using HTTP.

NetWareEnables Novell-based file sharing. Administration through Remote Desktop.

Table 3. File-Sharing Protocols Supported in Windows Storage Server 2003

Software Support Additional Information

Anti-virus Via third-party software.

Backup Via third-party software. Includes the backup utility NTBACKUP that uses VSS and SCSF to back up both system and user data withShadow Copies.

Distributed File System (DFS) Enables a single hierarchical mapping of all systems and shares on the network.

File Replication Service (FRS)Enables remote mirroring through replication.Synchronises data9.

Internet Information Services (IIS)Tool to host and manage Web pages on intranet or Internet. Version 6.0 supported in Windows Storage Server 2003.

Table 4. Software Supported in Windows Storage Server 2003

StorageManaging Storage Devices

Management and configuration of the storage disks

(both physical and logical) is under control of the VDS

(see “New Features” for more information).

Allocation of disk space to users is performed through

quotas, and can be managed through a user interface.

The Enterprise Edition of Windows Storage Server 2003

supports the Automated Deployment Service (ADS) as an

optional add-on. ADS is a scriptable service enabling

rapid and highly effective deployment of large numbers

of new servers.

Ensuring Availability of Stored Data

A number of existing technologies have been enhanced

and a number of new features have been added to

Windows Storage Server 2003 to help keep a business’s

data highly available. These technologies range from tools

to ensure hardware components are operating effectively

and at high performance, to technologies enabling

hardware (MPIO) and software (clustering) redundancy, to

data availability techniques for redundancy (VSS and RAID)

and high performance.

Disk Management Additional Information

Virtual Disk Service (VDS) Includes sample code for volume management.

Quota Management Enables administrators to limit the storage accessible by each user.

Automated Deployment Services

(ADS)

Enterprise Edition only. ADS enables administrators to perform script-based administration of large-scale deployments of Windows servers.ADS replaces Multi-Device Manager (MDM) in WP NAS 2.0.

Table 5. Disk and Deployment Management Capabilities in Windows Storage Server 2003

Reliability/Availability Additional Information

Volume Shadow Copy Service

(VSS)

Enables up to 512 point-in-time copies per volume, of which 64 are reserved for SCSF if enabled on the volume. This service replaces the Persistent Storage Manager (PSM) in WP NAS 2.0.

ClusteringProvides application failover. Windows Storage Server 2003 Enterprise Edition supports up to 8 nodes. (WP NAS 2.0 supports a maximum of 2 nodes.)

Software RAID 0, 1, 5RAID types provide differing levels of data protection and redundancy.VDS also enables hardware based RAID.

Multipath I/O (MPIO) Enables high performance and high availability through multiple paths to storage.

System MonitoringMonitors performance of the operating system. Allows system administrator to assess I/O performance with different devices.

Watchdog Timer Detects system hangs; can be programmed to reboot system after a given time.

Table 6. Features Enhancing System Reliability and Data Availability

2221

9 Web UI support for Distributed File System (DFS) does not include or enable FRS scenarios.

Key Improvements Since Windows Powered NAS 2.0Windows Storage Server 2003 has been improved in a

number of key areas relative to Windows Powered

NAS 2.0. This section highlights improvements in the key

areas of file serving performance, integrated snapshots,

and the user interface.

PerformanceAs a dedicated file server, the speed with which NAS boxes

can handle I/O read and write requests is a critical factor in

overall performance of systems on the network. Windows

system-based NAS boxes communicate with client systems

using the SMB (Server Messenger Block)10 or CIFS

(Common Internet File System) protocol for Windows systems.

For UNIX-based systems, the NFS (Network File System)

protocol is used.

SMB Performance

The industry standard in measuring SMB/CIFS file

server performance for Windows Clients is NetBenchTM

benchmarking software. File server performance is

measured as throughput (megabits per second) versus

number of clients.

Comparisons of Windows Storage Server 2003 and NAS 2.0

using the same hardware configurations directly capture

improvements in the Windows operating system performance.

These improvements stem from changes to the kernel

(improved caching, buffering, and the like), as well as changes

reflected in the use of SMB in 2003 versus CIFS in 2000.

Differences between studies capture differences attributable

to different hardware configurations.

In both internal Microsoft benchmarks using NetBench and a

commissioned third-party benchmark test, the performance

of Windows Storage Server 2003 is greatly enhanced

compared with NAS 2.0. In third-party Veritest comparison11

of file serving in Windows Storage Server 2003 and NAS 2.0,

peak throughput on Windows Storage Server 2003 is 35-85

percent faster than Windows Powered NAS 2.0, depending on

whether there are one, two, four or eight processors12 (See

Figure 1). Internal Microsoft tests, using a different hardware

configuration, put the overall throughput at 100 percent or

above for each of the four processor configurations.

NFS Performance

The industry standard for measuring NFS file server

performance for UNIX clients is based on the Spec SFS

benchmark program produced by the Standard Performance

Evaluation Corporation. Spec SFS scores file server

performance in terms of I/O Throughput Per Second

(IOPS). In internal MS tests13 using Spec SFS, file serving

performance increased from 5040 IOPS in NAS 2.0 to 7500

IOPS in Windows Storage Server 2003, a 50 percent increase.

NAS Management SoftwareDepending on the complexity of the deployment scenario, the

need for NAS management ranges from the minimal (plug

and play) to the considerably more complex (see Table 5).

Windows Storage Server 2003 provides a number of different

interfaces to meet such management needs, including both

local and Web-based UIs (see Table 7).

Management Additional Information

Web User Interface (UI)Enables administrators to manage users, create shares and control backups and similar tasks from any location on the network or Internet.

Remote Desktop Enables remote control of other systems for administration.

Table 7. Management Interfaces in Windows Storage Server 2003

Integrated Snapshots In NAS 2.0, point-in-time imaging (snapshot) technology is

available only through the integration of third-party advanced

backup software. In Windows Server 2003, snapshot

technology is part of the Volume Shadow Copy Service

(VSS) and is fully integrated into the operating system, thus

making it part of the Windows Storage Server 2003 package.

Snapshot technology enables open file backups and fast

restores. The technology is especially useful when the goal

is the restoration of individual files, which can be done by

the end user without the need for system administrator

intervention.

Improved End-User ExperienceWindows Storage Server 2003 has a number of enhanced

User Interfaces (UIs) for the end user and the system

administrator. On the client side, the Previous Versions

user interface (SCSF) allows end users to restore their own

files directly in the event of accidental deletion, overwriting

or file corruption. On the system administrator side, UIs for

volume defragmentation, task scheduling, folder and

share management, volume management, and UPS

management make administration of storage much

zmore convenient than before.

Figure 1. NetBench comparison of file-serving performance in NAS 2.0 (Windows 2000 Server) and Windows Storage Server 2003 (Windows Server 2003).

0

200

400

600

800

1000

1200

4P3P2P1P

Peak SMB Performance

Thro

ughp

ut (M

bps)

Windows 2000 Server Windows 2003 Server

2423

10 SMB Is Server 2003’s enhanced version of CIFS (native to Server 2000)

11 See the report at www.veritest.com/clients/reports/microsoft

12 It is important to note that these performance improvements are seen only when upgrade client software is loaded onto the client systems.

13 For configuration details, see Windows Storage Server 2003 OEM training guide.

The following are new features in Windows Storage

Server 2003.

Volume Shadow Copy Service

Virtual Disk Service

MPIO

DFS

Volume Shadow Copy Service (VSS)The VSS is an infrastructure that makes possible enhanced

data protection though high-fidelity backups, rapid data

restores, and data transport.

VSS is a component of the operating system and, as such,

is not accessed directly by users. Instead the VSS coordinates

with user applications, backup applications and storage

hardware to enable the creation of point-in-time Shadow

Copies of data on single or multiple volumes without

affecting performance significantly.

High-Fidelity Backups

Shadow copy creation is a highly effective means of protecting

data with several advantages over traditional tape backups

when the goal is not long-term archiving. Tape-based

technologies are time-intensive to run, impose a considerable

bandwidth burden on the local network, and can have data

inconsistency issues if applications are open during the

backup process. As a consequence, tape backups tend

to be scheduled relatively infrequently and at times when

applications are not in use (such as nights or weekends) – a

strategy that can work reasonably well for companies that do

not require 24x7 operations. In contrast, Shadow Copies can

be created in seconds, without the impact on network traffic

that tape backups impose. Additionally, because the Shadow

Copy process allows open files to be backed up without data

inconsistency issues, they can be scheduled at any time,

and much more frequently than tape backups.

Fast Restores

In the event of data loss, Shadow Copy restoration offers

significant advantage over tape restores. Because the

Shadow Copies can be saved on storage arrays on site, they

can be accessed directly, without the need to travel offsite

to a tape data vault, locate and bring back a tape. Even

more significantly, Shadow Copy restores take only minutes

to complete, while tape restores, depending on the type of

backup (full, differential or incremental) and the amount of

data, can take hours or even days to do correctly.

Shadow Copies for Share Folders

System administrators are not the only people to benefit

from the fast restore functionality enabled by VSS. System

administrators can activate SCSF, thereby enabling end users

who overwrite or accidentally delete a file to restore a previous

version of a file for themselves, rather than having to recreate

the file or request that a system administrator do a high-cost

single file restore from tape.

Shadow Copy Transport

All of the functionality discussed above is provided with the

in-box Shadow Copy technology on the operating system.

The exception to this is Shadow Copy transport among

systems – whether for backup, data mining, testing or fast

restores – that requires a hardware provider on the SAN.

In a DAS configuration, this data transport between servers

is physical. In a NAS-SAN configuration with pooled storage,

data on the SAN can be accessed (through masking and

unmasking) between servers. Although access to the storage

pool is shared, each server can only access the specific LUNs

(Logical Unit Number) assigned to it (since two servers cannot

both write to the same volume without potentially causing

data corruption). But using the hardware provider on the SAN,

a point-in-time Shadow Copy can be virtually “transported”

to another server for use, through the process of masking

and unmasking.

Windows Storage Server 2003 Features Virtual Disk Service (VDS)In order for a server to use new storage disks, they must first

be made accessible to the server and then formatted for use.

VDS controls the process of making storage accessible to

systems that need it. While it is irrelevant to application (or

the user) how the data is stored – whether it is on a single

physical disk or spanned across several disks (a logical unit),

in terms of data protection and performance, the impact of

how the data is stored is significant. Thus VDS can either

present a physical disk or a logical disk to a server.

Physical disks do not require the first two steps.

1. Create logical units; assign number IDs

(now referred to as LUNs).

2. Unmask LUNs to server.

3. Create partitions and volumes.

4. Format the file system.

Basic Disks. VDS is used to partition14 each physical

disk and to create the volumes that can be mapped to

drive letters for use. These volumes are known as “simple

volumes” and do not span multiple disks. Basic disks are

the legacy disks, predating Windows 2000 capabilities.

They do not offer the same performance and data

protection that dynamic disks offer.

Dynamic Disks. VDS can be employed to create dynamic

disks that can consist of either simple volumes or multi-

partition volumes15. Multi-partition volumes physically span

more than a single disk but, nevertheless, are logically

considered to be a single volume. Dynamic disks can be

spanned, striped (RAID-0), mirrored (RAID-1) or stripped

with parity (RAID-5), depending on the level of performance

and data protection desired. VDS can be used to expand

dynamic disks to make more space available to a volume.

Although many vendors provide NAS appliances preconfigured

with RAID, system administrators might want to use VDS to

customise the storage solution to meet specific data storage

needs, whether relating to capacity, performance or data

protection.

VDS can also be used to attach a NAS device to SAN. These

NAS “heads” contain only the file serving capabilities; for

highly scalable and highly available pooled storage, they

plug into a Fibre Channel SAN. Each storage unit on the SAN

must have its storage configured and made accessible to

the appropriate servers only. Since it is common for storage

on the SAN to be from multiple hardware vendors, prior to

Windows Server 2003 and Windows Storage Server 2003,

it was necessary for the system administrator to configure

each device using a vendor-specific storage management

application. Not only did this mean using hardware-specific

management utilities, it meant that, frequently, the system

administrator had to go physically to each storage device to

do each configuration.

The VDS of Windows Storage Server 2003 helps to alleviate

these administration complexities in a NAS SAN configuration

by providing a single management interface for multivendor

storage devices. The system administrator can manage all

storage devices directly from a single management console,

and query and configuration

operations are common across all managed devices.

In this scenario, VDS functionality is enabled through

hardware vendor support. Each hardware vendor must supply

a VDS “provider” for the storage hardware. The hardware

provider translates the VDS standard APIs (Application

Programming Interface) into instructions specific to the

storage device. With communication enabled between the

VDS and the storage hardware, the system administrator

can now use a single storage management interface to

communicate with multivendor storage devices.

Multipath I/O (MPIO)Multiple or redundant paths between storage devices and

the systems that use them enable persistent data availability

and high I/O performance. In essence, these technologies

provide for an alternative connection in case of failure of the

primary I/O path, and, optionally, multiple paths to improve

performance or balance loads.

MPIO software included in Windows Storage Server 2003

2625

14 Physical disks are divided into sectors; contiguous sectors are partitions. In the case of basic disks, the volumes are created within partitions, and are thus restrictedto a single disk.

15 Volumes can span one or more partitions on the same or multiple disks. Dynamic disk types include RAID configurations, and can offer better performance and reliability than basic disks.

is not a feature of the operating system, but is supported

through the Driver Development Kit (DDK). Multipathing

allows a host to have up to 32 paths to access an external

storage device, which facilitates failover and load balancing.

Multipathing technology is critical in ensuring highly available

data to businesses. In the past, multipathing was a solution

only available to large-scale enterprises; now this high-

availability solution is available to any organisation using only

Windows Storage Server 2003 (and Windows Server 2003)

technologies.

Microsoft’s MPIO delivers a standard and interoperable path

for communication between storage products and Windows

Server. With a platform upon which multiple third-party

storage systems can reliably interoperate, businesses have

greater choice when building a high-quality, highly available

network storage system, and system administrators will have

the flexibility to incorporate products from multiple vendors

into a single, interoperable and highly available storage

infrastructure.

Distributed File System (DFS)The DFS enables the system administrator to create single

hierarchical mapping of all systems and shares on the

network. By uniting files on different computers into a single

namespace, users do not have to sort through a network of

dozens of servers, each with their own separate directory

structure, but instead see the files as if they resided on a

single computer.

With the latest version of the server operating system, DFS

has been enhanced to allow multiple DFS roots on a single

server, thus reducing administrative and hardware costs

of managing multiple namespaces and multiple replicated

namespaces. In addition, DFS now delivers more reliable

load-balancing, better file replication between DFS sites and

servers, and closest-site selection for users accessing the

network. Closest-site selection ensures that in the event of

server failure or scheduled maintenance, users are routed

automatically to another server on the network that has a

replica of the data. For best performance and lowest cost,

clients are rerouted to the site closest to them.

NAS Deployment ScenariosThe following are common NAS deployment scenarios:

File Serving.

Server Consolidation.

Local and Remote Site Replication for Business Continuity.

NAS-SAN Fusion.

File ServingBusinesses need reliable file servers that can provide

highly available data at a reasonable cost. Off-the-shelf,

general-purpose servers are not typically configured with

fully redundant hardware components. Using a general-

purpose server for file serving and running applications can

compromise both tasks. In particular, file serving can be

negatively affected by the overhead associated with running

applications, as well as by the risks of system crashes

should an application fail. General-purpose servers have

the additional disadvantage of being platform specific,

necessitating a different file server to serve clients on

different platforms.

In contrast, NAS filers confer a number of advantages. NAS

appliances are designed for high reliability: they are built with

redundant disks, NICs (for failover data paths), and power

supplies. This redundancy of hardware components makes

NAS devices highly reliable file servers helping to ensure

highly available data.

Because NAS devices built on Windows Storage Server

2003 are dedicated file servers, they do not carry application

overhead, and they are not vulnerable to application-related

problems. Moreover, because Windows Storage Server 2003

supports multiple file sharing protocols, file serving to clients

on Windows, UNIX or Macintosh computers, and sharing

between them, can be accomplished without the need for

a specialised file server for each platform.

Server ConsolidationAs companies add more and more servers to meet demands

for increased storage capacity, equipment, licensing,

maintenance (power, space, servicing) and management

costs all escalate.

Adding a device based on Windows Storage Server 2003

to the network allows businesses to consolidate multiple

file servers into a single more powerful NAS device. Given

the broad file serving capabilities of Windows Storage

Server 2003, even file servers running on different platforms

(such as UNIX or Novell) can be consolidated onto one NAS

Figure 4. File serving between network clients and Windows Storage Server 2003.

WindowsStorage Server

2003

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Figure 5. Consolidation of several multiplatform servers onto a single Windows Storage Server 2003 NAS device. This scenario enables the consolidation of tape drives inot a single tape tray.

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Windows Storage Server 2003

Consolidate Multiple File Servers onto

Windows Storage Server 2003

Corporate LAN

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Figure 6. Replication of data between NAS Windows Storage Server 2003 devices deployed at different branch sites.

Figure 7. Windows Storage Server 2003 (NAS “head”) integrated into Storage Area Network. Note Unix – change to UNIX

Windows

Corporate LAN

Corporate SAN with Shared Disk

Clients

Unix

WindowsStorage Server

2003

Switch

device, greatly simplifying management across systems.

Related equipment, such as backup devices, can also be

consolidated. System management is much simpler with

fewer devices requiring space, servicing (such as applying

patches or maintaining versioning), and backup and restore

services. For every NAS device replacing multiple existing

servers16, the associated licensing costs are eliminated.

Local and Remote Site Replication for Business Continuity NAS servers using Windows Storage Server 2003 software

technologies enable businesses to build fault-tolerant

solutions designed to keep data highly available.

NAS devices on a LAN can use the replication technologies

to replicate data between one NAS device and another. In

the event of network failure or the outage of a NAS device,

a second NAS device can assume the identity of a non-

functioning filer and continue serving files to clients without

interruption of services. When the non-functioning NAS device

returns, it takes back its identity, resynchronises its data with

the active NAS device, and resumes file serving.

This process of replication and failover also works on a Wide

Area Network (WAN). Replication and synchronisation occurs

over the WAN between NAS devices. Should one branch site

succumb to disaster or be shut down for a planned outage,

clients accessing that NAS device are redirected to a second

NAS device at a different branch.

NAS devices are also useful to remote sites for a different

reason. Branch offices often do not have the IT staffing

expertise to deploy general-purpose servers effectively.

Because they are so simple to deploy and maintain, NAS

file servers are the perfect plug-and-play solution for these

remote sites.

NAS-SAN FusionNAS devices can be integrated seamlessly into a SAN,

providing clients access to unlimited storage. In this

configuration, NAS storage is separated from the NAS filing

function and placed on the SAN. The NAS head now acts as

a gateway to the SAN, controlling distribution of the data over

the network and providing clients with maximum scalability

and high-performance storage solutions.

NAS-SAN fusion also enables system administrators to

move NAS backups off the LAN onto the storage network for

highly efficient and extremely fast backups that do not affect

LAN performance.

Windows Storage Server 2003 provides scalable, high-

performance storage solutions to businesses of all sizes.

Built on the Windows Server 2003 operating system, this

successor to Windows Powered NAS broadens usability and

interoperability for both end users and system administrators.

Using Shadow Copies for Shared Folders, end users are

empowered to recover their own lost data without IT

intervention, thereby improving their own efficiencies and

helping the business save money. System administrators

benefit from the seamless integration of Windows Storage

Server 2003 into existing networks, multiplatform file-serving

capabilities, and built-in point-in-time imaging capabilities for

highly efficient backup and restores.

Summary

See the following resources for further information:

Microsoft Windows Network Attached Storage Home

www.microsoft.com/windows/storage/default.mspx

Technical Overview of Windows Server 2003 Storage Management

www.microsoft.com/windowsserver2003/techinfo/overview/storage.mspx

Windows Server 2003 Storage Services

www.microsoft.com/windowsserver2003/technologies/storage/default.mspx

Windows Server 2003 File Server, Web Server, and Active Directory Performance Testing (4/03)

www.veritest.com/clients/reports/microsoft

Microsoft Windows Server 2003 versus Linux Competitive File Server Performance Comparison (4/03)

www.veritest.com/clients/reports/microsoft

Related Links

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of publication.

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16 The number of servers that can be consolidated on NAS device depends how powerful the server capabilities are and how many clients are served. Microsoft tests have demonstrated that up to 25 Windows NT servers can be consolidated into a single NAS device

ServersCorporate LAN

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© 2003. Microsoft Corporation. All rights reserved. Microsoft, Active Directory, Windows, Windows NT, Windows Server and the Windows logo are either registered trademarks or trademarks of

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