maximizing storage efficiency in windows server 2012 r2 and windows storage server 2012 r2

Maximizing Storage Efficiency in Windows Server 2012 R2 and Windows Storage Server 2012 R2 Published January 2014

Abstract: This document examines features in Windows Server 2012 R2 and

Windows Storage Server 2012 R2 that can be used to maximize storage efficiency.

Topics include:

How growing data volumes are driving the need for greater storage efficiency.

An overview of the Microsoft storage stack, including its performance and cost-

effectiveness compared to a traditional storage area network (SAN).

Built-in features that can be quickly deployed to improve storage efficiency,

including Data Deduplication, Storage Spaces (storage virtualization), and Thin

Provisioning and Trim.

Supported deployment scenarios, including data center and remote office or

branch office.

Maximizing Storage Efficiency in Windows Server 2012 R2 and Windows Storage Server 2012 R2

© 2014 Microsoft Corporation. All rights reserved.

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Some examples are for illustration only and are fictitious. No real association is intended or inferred.

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ContentsExecutive Summary...................................................................................................1

The Need for More Efficient Storage...........................................................................2

Enterprise-Class Storage in Windows Server..............................................................3

All You Need for Highly Efficient Storage is In-the-Box...............................................4

Data Deduplication.....................................................................................................5

Storage Spaces...........................................................................................................7

Thin Provisioning and Trim.........................................................................................9

Related Features......................................................................................................10

Deployment Scenarios..............................................................................................11

Conclusion and Additional Resources.......................................................................13

Appendix A: SAN Performance at a Fraction of the Cost..........................................14


Executive SummaryFew would disagree that affordable, reliable storage is an essential component of

any technology-enabled business. When it comes to data storage, two facts hold

true:

For most companies, data volumes are continuing to grow at a rapid pace.

Many of those companies are adopting ways of using storage more efficiently

in order to minimize storage-related costs.

Windows Server 2012 R2 Standard and Datacenter (and by extension, Windows

Storage Server 2012 R2 Standard) provide everything that you need for highly

efficient storage that can scale to support the largest workloads. Key technologies

that contribute to this capability include:

Data Deduplication, which can reduce the amount of disk space required for

common storage workloads by 30-90 percent based on Microsoft internal

testing.

Storage Spaces, a technology that enables you to virtualize storage by

grouping industry-standard disks into storage pools, and then create virtual

disks (called storage spaces) from the available capacity in the storage pools.

Thin Provisioning and Trim, which enable you to deploy only the disk space

you need today, expand dynamically when needed, and automatically reclaim

storage that is no longer needed.

The benefits of using Windows Server 2012 R2 to maximize storage efficiency

include:

Reduced/deferred storage costs. With the technologies in Windows Server

2012 R2, you can store more logical data in less physical disk space, purchase

only the physical storage you need today, expand dynamically as needed, and

avoid operating costs associated with supporting unused disk capacity until it

is actually needed.

Low acquisition costs. All features needed to maximize storage efficiency

are included in-the-box with Windows Server 2012 R2 (Standard and

Datacenter) and Windows Storage Server 2012 R2 Standard, and can be used

without any additional hardware, software, or licensing fees.

Maximizing Storage Efficiency in Windows Server 2012 R2 and Windows Storage Server 2012 R2 5

Fast, easy deployment. With Windows Server 2012 R2, there’s no new

hardware or software to deploy. All technologies for maximizing storage

efficiency are built into the operating system and can be turned-on and

configured in just a few minutes.

Ease of management. Server Manager in Windows Server 2012 R2 can

provide a single view of all your storage, across your data center. System

administration tasks can also be performed using Windows PowerShell,

enabling you to automate provisioning of new storage spaces and virtual disks

whether you have one server or multiple servers.


The Need for More Efficient StorageAccording to recent studies, more than 40 percent of information technology (IT)

staffs in the world today are encountering significant increases in data volumes. 1 At

the same time, traditional SAN solutions are becoming more expensive to deploy

and expand. Fortunately, new technology advances are providing a partial answer

to these challenges:

Today’s powerful, industry-standard servers provide an attractive alternative to

costly, proprietary SAN storage controllers.

10 Gbps and faster network cards are enabling companies to use cost-effective

Ethernet technology to remotely access shared storage.

Leading technology companies have recognized this opportunity to reinvent

enterprise storage and are bringing new solutions to market. Of course, making this

work requires a whole lot of “secret sauce”—as required to turn a commodity server

into a full-featured storage controller.

But what exactly is needed from that software? Or, more specifically, which storage

features can help you control storage costs in the face of growing data volumes?

Again, the answer can be found in the market, among the many companies are

adopting the latest ways of using storage more efficiently. These technologies

include:

Data deduplication, which makes storage more efficient by minimizing

redundant data on a disk.

Storage virtualization, which enhances storage scalability through the

abstraction of logical storage from physical storage.

Thin provisioning and trim, which enable you to create virtual disks that

appear larger than their physical storage capacity, provision additional storage

as needed, and reclaim that storage when no longer needed.

If you’re not already thinking about adopting a highly efficient storage infrastructure

based on industry standard hardware, you may want to consider one. But where can

you get the technologies needed to maximize storage efficiency, how do they work,

how are they deployed, and what do they cost?

1 Source: Agile BI, Complementing Traditional BI to Address the Shrinking Business-Decision Window, November 2011, Aberdeen Group, Inc.


The remainder of this paper examines these questions from the perspective of

Windows Server 2012 R2 and Windows Storage Server 2012 R2, which is based on

Windows Server 2012 R2.


Enterprise-Class Storage in Windows ServerWith Windows Server 2012 R2, you can take advantage of a proven, enterprise-

class data center and cloud platform that can scale to run the largest workloads.

Delivered as a dynamic, available, and cost-effective cloud solution, Windows

Server 2012 R2 provides automated protection and cost-effective business

continuity to keep your business up and running, all while simplifying storage

management and protecting your existing storage investments.

The Microsoft Storage StackWindows Server 2012 R2 integrates SAN features with the power and familiarity of

Windows Server, enabling you to easily scale up to meet growing storage needs on

low-cost, industry-standard hardware. Even better, you can achieve SAN-like

performance and reliability while significantly reducing storage costs in terms of

$/IOPS and $/TB. Appendix A compares the performance and cost of the Microsoft

storage stack to a traditional SAN, as determined by a study performed by ESG Lab.

Figure 1 shows the Microsoft storage stack and its key components:

Hyper-V workloads and SQL Server databases that access storage through

existing networking infrastructure over the enhanced SMB 3 protocol

Storage exposed through Windows Server-based Scale-Out File Servers

Storage based on industry-standard disks and JBOD enclosures—provisioned

using Storage Spaces


Figure 1. Diagram of the Microsoft storage stack.


All You Need for Highly Efficient Storage is In-the-BoxThe Microsoft storage stack is more than just enterprise-ready; it’s also ready to

help you maximize storage efficiency. Windows Server 2012 R2 Standard and

Datacenter (and Windows Storage Server 2012 R2 Standard) provide all that you

need for this in-the-box, ready to use, without additional product keys or licensing

fees. When combined with the low acquisition costs for Windows Server 2012 R2 or

Windows Storage Server 2012 R2 running on industry-standard hardware, this

provides a level of value that is hard to match with any other storage platform.

Key technologies in Windows Server 2012 R2 that can help maximize storage

efficiency include:

Data Deduplication, which uses sophisticated data reduction functionality to

reduce the amount of physical disk space required to store a given amount of

logical data. Data duplication can be used on any server, by itself, or with

Microsoft BranchCache to extend branch office storage capabilities.

Storage Spaces, which is Microsoft’s implementation of storage virtualization.

It enables you to group industry-standard disks into storage pools, and then

create virtual disks (called storage spaces) from the available capacity in those

storage pools. When needed, additional capacity can easily be added to a

storage space by simply bringing new disks into the underlying storage pool or

pools.

Thin Provisioning and Trim. When you create a virtual disk (including a

storage space), you can either choose thin or fixed provisioning. With thin

provisioning, you can create virtual disks that appear larger than the current

storage pool capacity and then provision additional storage as needed.

Similarly, trim enables you to reclaim storage that is no longer needed.

These features in Windows Server 2012 R2 are designed to work with its many

other storage features, including SMB 3.0, Hyper-V, Failover Clustering, Cluster

Shared Volumes (CSV), Storage Quality-of-Service (QoS), and Hyper-V Replica. All

storage features are accessible through a single, integrated management interface,

making it simple to deploy scalable, highly available, easily managed storage that

can support both traditional file server roles and application workloads—all on cost-

effective, industry standard hardware.


You can also choose how to buy: build (or spec) your own system using industry-

standard components and Windows Server 2012 R2, or purchase a storage

appliance with Windows Storage Server 2012 R2 preinstalled. Either way, all you

need for highly efficient storage is in-the-box—so you’ll be all set to maximize

storage efficiency and reduce your storage costs.


Data DeduplicationData Deduplication, a storage efficiency feature first introduced in Windows Server

2012, helps address the ever-growing demand for file storage. Instead of expanding

the storage used to host data, Windows Server automatically scans through your

disks, identifying duplicate chunks and saving space by storing these chunks only

once. This functionality saves you money by optimizing your existing storage

infrastructure. In addition, deduplication offers even greater savings by extending

the lifespan of current storage investments.

How Data Deduplication WorksData Deduplication runs in the background on a file server, inspecting “cold” files

that are not currently in use. Data Deduplication can also be used to optimize

virtual disks for running VDI workloads—provided that the storage and compute

nodes for the VDI infrastructure are connected remotely via the SMB protocol.

During the deduplication process, the deduplication engine:

Examines and segments files into small, variable-sized “chunks” of 32KB–128KB in size.

Identifies duplicate chunks that appear in more than one file.

Maintains a single copy of each chunk in a compressed format in a central repository, which is called a “chunk store,” and resides in the System Volume Information folder.

Replaces each deduplicated file with a much-smaller reference (called a reparse point) that indicates which chunks are used by the file.

When a deduplicated file is read, a filter in the read-path reassembles the file in a

manner that is transparent to the calling application or user. Deduplication has a

cache to avoid going to disk for repeatedly accessed chunks. (If multiple users are

accessing deduplicated files that contain the same chunks at the same time, the

caching of these chunks at the file re-assembly level will speed-up access times for

all users.)

Data Deduplication also throttles CPU and memory usage, enabling implementation

of large volumes without impacting server performance. In addition, metadata and

preview redundancy help prevent data loss due to unexpected power outages.

Checksums, along with data integrity and consistency checks, help prevent

corruption for volumes configured to use Data Deduplication. Routine compression


run times can also be scheduled for off-peak times to reduce any impact those

operations might have on data access.

Where Data Deduplication Delivers Significant ResultsWhen Data Deduplication is employed, the resulting increase in storage efficiency

depends on the type of data being stored. From both internal testing and that

performed by ESG Lab, Data Deduplication has shown storage savings of 25-60

percent for general file shares and 90 percent for OS VHDs. This is far above what

was possible with Single Instance Storage (SIS) or New Technology File System

(NTFS) compression. Figure 2 shows the increase in storage efficiency provided by

Data Deduplication for various storage workloads.

Figure 2. Gains in storage efficiency provided by Data Deduplication for various

workloads.

Microsoft supports the use of Data Deduplication for most cold files. (SQL Server

and Exchange Server files, even if cold, will not benefit much from Data

Deduplication. Using Data Deduplication on these types of files is not

recommended, nor is it supported by Microsoft due to performance considerations.)


Data Deduplication is also supported for the optimization of virtual disks in VDI

deployments. Data Deduplication was tested to ensure that it performs correctly on

general virtualization workloads; however, efforts were focused on ensuring that the

performance of optimized files is adequate for VDI scenarios. For non-VDI scenarios

(general Hyper-V VMs), Microsoft cannot provide the same performance guarantees.

As a result, Microsoft does not support deduplication of arbitrary, in-use VHDs with

Windows Server 2012 R2. However, because Data Deduplication is a core part of

the storage stack, there is no explicit block in place that prevents it from being

enabled on arbitrary workloads.


Storage Spaces Storage Spaces in Windows Server 2012 R2 gives you the ability to consolidate all

of your Serial Attached SCSI (SAS) and Serial Advanced Technology Attachment

(SATA) connected disks—regardless of whether they are Solid State Devices (SSDs)

or traditional hard disk drives (HDDs)—into storage pools. After you have created

these pools, you can then create logical storage devices from them, called storage

spaces.

Figure 3 provides a conceptual view of Storage Spaces and Storage Pools.

Figure 3. Storage Spaces conceptual view.

Storage Spaces virtual disks work the same as regular Windows disks. However,

they can be configured for different resiliency schemes, such as mirroring and

parity.

Storage Spaces is compatible with other Windows Server 2012 R2 storage features,

including SMB Direct and Failover Clustering, so you can use simple inexpensive

storage devices to create powerful and resilient storage infrastructures on a limited

budget. At the same time, you can maximize your operations by utilizing industry-


standard hardware to supply high-performance and feature-rich storage to servers,

clusters, and applications alike.

Storage TiersWindows Server 2012 R2 introduces a new, policy-based, tiered storage mechanism

for Storage Spaces. Storage tiers provide more flexibility for hot and cold workloads

and supports industry standard enclosures with SATA, SAS, and SSD devices.

Storage Spaces assigns data to storage tiers within a tiered storage space based on

how frequently the data is accessed:

Storage Spaces automatically moves hot data (data that changes frequently)

to the faster, but more expensive, SSD media. All data starts as hot data.

Storage Spaces moves cold data (data that changes infrequently) to the

slower, less expensive, hard disk drives. If cold data becomes hot, it

automatically moves to the SSD media. If hot data becomes cold, it moves to

the hard disk drives.


Thin Provisioning and TrimWhen you create a virtual disk (including a storage space), you can either choose

thin or fixed provisioning. With thin provisioning, you can create virtual disks larger

than the current storage pool capacity and then add disks later to support needed

growth. As a result, administrators only need to purchase the physical storage

needed and can expand dynamically when necessary.

Use of storage tiers requires fixed provisioning. Use of the Thin Provisioning feature

in Windows Server is only supported for standalone, non-clustered configurations.

(This does not apply to the use of thin provisioning functionality that is built-into a

storage array.)

Trim provides a mechanism that enables applications to give up storage when it is

no longer needed, thereby ensuring maximal use. For example, assume a company

stores its Hyper-V VMs on logical disks created with Storage Spaces. With trim,

when a VM deletes a large file, it communicates the deletion to the host, which then

communicates it to the storage space. As a result, the storage space automatically

reclaims this space, making it available for use again.


Related FeaturesThe following features—all built into Windows Server 2012 R2 (Standard and

Datacenter) and Windows Storage Server 2012 R2 Standard—are also applicable to

common scenarios that can benefit from improved storage efficiency.

Hyper-V ReplicaHyper-V Replica provides asynchronous replication of VMs for purposes of business

continuity and disaster recovery. If a failure occurs at a primary site, the

administrator can manually failover production VMs to a Hyper-V server at a

recovery site. The VMs recover to a consistent point-in-time, and are accessible to

the rest of the network in near real-time. After the primary site comes back, the

administrator can manually revert the VMs to the Hyper-V server at the primary

site.

Online VHDX ResizeVirtual machines that host applications with service-level agreements must be able

to increase and decrease the size of dynamic disks while the virtual machine is

running versus having to take the virtual machine and applications offline to do it.

Online VHDX Resize in Windows Server 2012 R2 offers a way to perform online

VHDX resize operations (both expanding and trimming). With Online VHDX Resize,

you can grow a SCSI virtual disk with no downtime, and expand and shrink a volume

within a guest without downtime.

Storage Quality-of-Service (QoS)When you virtualize databases or certain virtual machine workloads that are

storage heavy, you need to be sure that the databases get the IO bandwidth they

need and that you have the ability to monitor storage bandwidth usage. With

storage QoS, a new feature of Hyper-V in Windows Server 2012 R2, you can set the

maximum IOPS that the virtual machine can use. This can prove useful if you have

an extraction, transform, load (ETL) job that runs during normal business hours but

that you want to prevent from using all available IO on the virtual switch. QoS can

throttle the available bandwidth to the guest network adapter when it reaches the

limit that you set. You can also set a minimum amount of bandwidth so that it’s

available even if other processes need resources.


Deployment ScenariosThe technologies for maximizing storage efficiency in Windows Server 2012 R2 are

designed to work equally well in your main data center or a remote office or branch

office.

Data centerFigure 4 shows a typical “standalone” configuration for a main data center.

Figure 4. Typical data center deployment.

Remote Office or Branch Office


Figure 5 shows a typical deployment configuration for a remote office or branch

office.

Figure 5. Typical remote office or branch office deployment.

In the remote office or branch office scenario, two additional technologies that are

built into Windows Server 2012 R2 are often useful: BranchCache, and DFS

Replication, both of which you can think of as “efficient synchronization”

technologies.

BranchCache

BranchCache is a wide area network (WAN) bandwidth optimization technology.

When users access content on remote servers, BranchCache copies that content

from your main office or hosted cloud servers and caches it at branch office

locations, allowing client computers at branch offices to access the content locally

rather than over the WAN. BranchCache works seamlessly with Data Deduplication,

Storage Spaces, and other Windows Server 2012 R2 storage features.

DFS Replication

DFS Replication is a multi-master replication engine that supports replication

scheduling and bandwidth throttling. It uses a highly-efficient algorithm known as

remote differential compression (RDC) to efficiently update files over a limited-

bandwidth network. RDC detects insertions, removals, and re-arrangements of data

in files, enabling DFS Replication to replicate only the changed file blocks when files

are updated. DFS Replication also works seamlessly with Data Deduplication,

Storage Spaces, and other Windows Server 2012 R2 storage features.


Conclusion and Additional ResourcesThe Microsoft storage stack can handle most enterprise workloads for a fraction of

the price per IOPS and per TB as traditional SANs. With shrinking budgets and

increased demand for storage, organizations need to take a fresh look at Windows

Server 2012 R2 as a storage solution for workloads that do not require the

advanced features and capabilities of traditional SAN storage.

Windows Server 2012 R2 provides a new, less-expensive option for high-

performance, resilient, enterprise-grade storage. Many companies have already

begun to move toward more efficient storage infrastructures, and with the Microsoft

storage stack, you can get the storage efficiency, reliability, and manageability you

need—all at an affordable price.

Additional ResourcesMore information about Windows Server 2012 R2 File and Storage Services can be

found at

http://technet.microsoft.com/en-us/library/hh831487.aspx

More information on Data Deduplication can be found at


More information on Storage Spaces can be found at


More information on Hyper-V (including related features in this paper) can be found

at http://technet.microsoft.com/en-us/library/hh831531.aspx

More information on BranchCache can be found at


More information on DFS Replication can be found at

http://technet.microsoft.com/en-us/library/jj127250.aspx


http://technet.microsoft.com/en-us/library/jj127250.aspx






Appendix A: SAN Performance at a Fraction of the CostTo illustrate the cost and performance differences between a traditional SAN

storage solution and one built on the Microsoft stack, the Enterprise Strategy Group

(ESG) tested response times of virtual machines (VMs) using different storage

topologies (Fibre Channel-SAN, Internet Small Computer System Interface (iSCSI)-

SAN, Storage Spaces over SMB with RDMA NICs). The results (see Figure 6) measure

SQL Server response times for transactions in milliseconds when running 2, 4, 6,

and 8 instances of SQL Server with each type of remote storage.

Figure 6. Response time comparison.

The time comparison between the different instances illustrates several interesting

conclusions:

Performance scales linearly as the number of VMs increases from two to eight.

The performance differences between the storage configuration test scenarios

are negligible.

The performance of Storage Spaces over SMB with RDMA is slightly faster (1-4

percent) than iSCSI/FC SAN test scenarios.


8

6

4

2

0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10

SQL Server Response Time Comparison(OLTP Workload, Windows Server 2012, SQL Server 2012)

(Less is better)

Storage Spaces over SMB FC SAN iSCSI SANStorage Spaces over SMB with RDMA

Average Transaction Response (s)

Nu

mb

er

of

Hyp

er-

V v

irtu

al m

ach

ines

The performance of Storage Spaces over SMB is slightly slower (averaging 3

percent) than iSCSI/FC SAN.

ESG Lab also converted the raw capacity of TBs to gigabytes (GBs) and divided the

total cost of acquisition by the GB, resulting in the commonly-used metric of $/GB

(see Figure 7). Similarly, to the overall cost of acquisition, iSCSI- and Fibre Channel

SANs proved to be almost twice the cost of the Microsoft file-based storage offering

with Storage Spaces and RDMA.

FC SAN iSCSI SAN File-based Storage with Spaces, SMB, RDMA, SAS

JBOD

$0

$2

$4

$6

$8

$10

$6.65 $6.19

$3.33

$/GB Cost of Acquisition Analysis(14.4TB of raw capacity from 24 10K 600GB SAS drives)

$/G

B

Figure 7: A comparison of cost acquisition between model scenarios

ESG Lab did not factor in the cost of management and maintenance. Because many

organizations have Microsoft and Windows experts, as well as storage experts, they

can manage the Windows storage without the need for additional training. Many

SAN IT vendors require vendor-specific storage specialists to provision, manage,

and monitor the storage infrastructure.

The full ESG Lab report can be found here.


http://download.microsoft.com/download/8/0/F/80FCCBEF-BC4D-4B84-950B-07FBE31022B4/ESG-Lab-Validation-Windows-Server-Storage.pdf

maximizing storage efficiency in windows server 2012 r2 and windows storage server 2012 r2

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