Networked Storage “Need-to-Knowscdn.ttgtmedia.com/searchStorage/downloads/ITDA... · NetApp and Oracle Corp. (in the Sun ZFS Storage 7000 series appliance) have been early advocates

Networked Storage “Need-to-Knows”

Thinking about upgrading your storage array soon?

Before you make any decisions, explore this guide to catch up on all of the latest trends, techniques and

technologies in the networked storage market today.

Page 1 of 32

Networked Storage Need-to-Knows

Contents

NAS Need-to-Knows

File storage focuses on

scalable NAS

Scale-up vs. scale-out

NAS

NAS options: Pros and

cons of scale-out and

scale-up

Improve NAS

management with private

storage clouds

SAN Need-to-Knows

FC dominates enterprise

storage networking

Storage networking

infrastructure trends

iSCSI performance Q&A

Primer: Getting started

with iSCSI

Unified Storage Need-to-Knows

Understanding unified

storage architecture

Unified storage growing

in popularity

Unified storage

advantages

Whether it’s the need for more capacity, to improve performance or for the ability to support new applications, there are more reasons than ever to upgrade your storage array. Fortunately for you, these technologies have likely become a lot more sophisticated since your last purchase.

So what do you need to know now before making an upgrade? Find out in this exclusive guide.

Catch up on what’s new in the networked storage market – from the latest trends to the newest technologies – and help ensure your latest storage array can adhere to your current and future storage requirements.

Contents

NAS Need-to-Knows

File storage focuses on scalable NAS..….……………….…….…………Page 2

Scale-up vs. scale-out network-attached storage..…..……………..…...Page 8

NAS options: Pros and cons of scale-out and scale-up.………….…...Page 10

Improve NAS management with private storage clouds……………....Page 13

SAN Need-to-Knows

FC technology still dominates enterprise storage networking………..Page 15

Storage networking infrastructure trends must figure in upgrade plans

…….…………………………………………………………………………Page 18

iSCSI performance: An expert discussion with Dennis Martin..………Page 22

Getting started with an iSCSI storage system: An iSCSI primer..……Page 25


Understanding unified storage architecture...……..……………………Page 27

File-based growth increases popularity of unified storage systems.…Page 28

Unified storage systems offer cost savings and management advantages

……………………………………………....…………………………….…Page 29

Page 2 of 32


Contents

NAS Need-to-Knows


scalable NAS


NAS



scale-up

Improve NAS


storage clouds

SAN Need-to-Knows


storage networking

Storage networking




with iSCSI





in popularity

Unified storage

advantages

File storage focuses on scalable NAS Network-attached storage (NAS) systems are at the heart of burgeoning file

data stores. But scalable NAS systems will have to evolve to meet new

capacity, accessibility and management needs. The evolving features and capabilities of network-attached storage (NAS) systems are being driven by a rapidly changing computing landscape and a set of trends and technologies that are morphing NAS into devices that bear little resemblance to traditional corporate file stores. To start, next-generation NAS is no longer confined to corporate data centers but is increasingly used to power cloud services with their need for unbridled scalability. But even in enterprises, the rising interest in big data and the accelerating growth of unstructured data are pushing scalable NAS to the top of the next-gen NAS feature list. A 2011 study by Framingham, Mass.-based IDC found that the world's data is doubling every two years, and predicted enterprises will have to deal with 50 times more data and 75 times more files in the next decade. The consumerization of IT and the fading of boundaries between personal computing and the workplace require NAS systems to be securely and easily accessible from a wide range of devices. In addition, the continuous need for more efficient IT and the unstoppable journey to a virtualized IT infrastructure are pushing for the incorporation of new features into next-generation NAS systems. Scalability, accessibility and manageability are the key areas in which next-gen NAS systems will be measured to determine if they're up to the task in a world of clouds and proliferating consumer devices. NAS scalability Scale-out architecture. Until recently, storage systems in which two storage controllers share the workload and provide failover for each other dominated the enterprise space. Capacity scaled by adding disks and shelves, and performance by adding additional processors, memory, spindles and upgrading storage controllers to the next level. Eventually, and often rather quickly, a scalability limit was reached, and the only available options were to either add another storage system or do a fork-lift upgrade and replace the existing NAS. The results were sprawling NAS silos and bloated storage budgets. While dual-controller storage systems worked in the 20th century, they've failed to efficiently support the unchecked growth of unstructured data in the 21st century. With established NAS vendors sticking with traditional architectures, in the early 2000s, startups like Isilon and Ibrix ventured into multinode NAS systems that scale proportionally as nodes are added. Their systems were first adopted in vertical markets like health care and the gas and oil industry where large unstructured files prevail; since then, the systems have increasingly found their way into the enterprise. It took established storage

Page 3 of 32


Contents

NAS Need-to-Knows


scalable NAS


NAS



scale-up

Improve NAS


storage clouds

SAN Need-to-Knows


storage networking

Storage networking




with iSCSI





in popularity

Unified storage

advantages

vendors almost a decade to yield to the pressure and success of scale-out architecture NAS; lacking scale-out experience, they sought to acquire scale-out pioneers. The acquired technologies have either been incorporated into existing systems, as NetApp Inc. did with Spinnaker, or simply repackaged, as EMC Corp. is doing with Isilon (EMC Isilon), Hewlett-Packard (HP) Co. with Ibrix (HP Ibrix X9000) and Dell Inc. with Exanet (PowerVault NX3500). With the majority of large storage vendors now on board, scale-out has become the architecture of choice for NAS. The benefits of scale-out NAS are compelling:

Scalable performance in I/O and throughput

Scalable capacity

Lower cost

Improved high availability (HA)

Simplified management by being able to manage a single large NAS rather than NAS silos

At this point, the ability to scale horizontally and manage a multinode NAS system as a single storage system with a global namespace are must-haves and should top anyone's NAS wish list. By the same token, it's important to realize that not all scale-out NAS systems are equal; while each vendor claims to lead, there are significant differences in how they scale, how they support a global namespace, the number of file systems and files per file system they support, the makeup of their storage pool and how they manage metadata. Tiering solid-state drives (SSDs), disk and cloud. Storage tiering and the ability to efficiently support solid-state storage are instrumental to scale costs efficiently. Next-generation NAS systems need to support SSDs, disk and cloud tiers. Almost all NAS systems have some level of SSD support, but there are substantial differences in how SSD is leveraged and the tiering methods used to ensure that active data remains on fast flash tier and stale data on slower disk or cloud tiers. In its most basic and common implementation, SSDs are added to a NAS system to supplement mechanical drives, with files and applications allocated to appropriate tiers manually. Despite a consensus that data movement between tiers needs to be automatic, the support for automated data tiering varies significantly in contemporary NAS offerings. "Isilon supports SAS, SSD and SATA as part of a storage pool, but today we don't move data between tiers automatically," said Sam Grocott, vice president of marketing at EMC Isilon. Flash as cache is another way to supplement a NAS with solid-state storage. While more complex to implement and requiring a change in the underlying storage architecture, flash cache has several advantages over simply

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Contents

NAS Need-to-Knows


scalable NAS


NAS



scale-up

Improve NAS


storage clouds

SAN Need-to-Knows


storage networking

Storage networking




with iSCSI





in popularity

Unified storage

advantages

substituting disks with SSDs (at least as long as the cost of SSD remains an order of magnitude higher than that of mechanical disk drives):

A cache will always keep the most active data in SSD without the need for tiering policies

It benefits all files on the storage system

A cache moves data at a sub-file level between tiers NetApp and Oracle Corp. (in the Sun ZFS Storage 7000 series appliance) have been early advocates of using flash as cache. The combination of a flash cache and low-cost, high-capacity SATA drives can challenge the performance of high-end disk arrays but cost less. "Next-gen NAS should support both tiering with cache, as well as by policies," EMC's Grocott said. While solid-state storage aids performance and may yield lower overall storage costs, storage clouds enable unprecedented levels of capacity scalability. Today, the integration between traditional NAS systems and the cloud is usually accomplished using cloud gateways, but next-gen NAS systems are expected to support native cloud integration to enable virtually infinite scalability. While cloud computing accounts for less than 2% of IT spending today, IDC estimates that by 2015 nearly 20% of information will be touched by cloud providers -- that is, somewhere in a byte's voyage from creation to disposal it will be stored or processed in the cloud. Cloud will simply be another tier and the movement of data between the cloud and other tiers needs to be automatic. "Next-gen NAS should have the ability to talk to a cloud natively; today, EMC can do it to Atmos leveraging Rainfinity," said Greg Schulz, founder and senior analyst at Stillwater, Minn.-based StorageIO. NAS accessibility NAS systems have been confined to data centers and accessibility via NFS and CIFS file-system protocols. With the rise of cloud computing and the proliferation of mobile devices, limited connectivity to files on NAS arrays has become an obstacle. To have data concurrently available on smartphones, tablets and traditional computing devices, savvy users have taken advantage of services like Dropbox. But that often means they've taken files out of secure corporate NAS stores, put them on their laptops and desktops, and synchronized them to all their devices. To the consternation of corporate IT, which had been struggling to mitigate the security risk of USB memory sticks, new cloud services like Dropbox suddenly posed a new and bigger threat to confidential corporate data.

Page 5 of 32


Contents

NAS Need-to-Knows


scalable NAS


NAS



scale-up

Improve NAS


storage clouds

SAN Need-to-Knows


storage networking

Storage networking




with iSCSI





in popularity

Unified storage

advantages

Traditional storage systems will need time to respond to the new

requirements to efficiently support simple and secure access for mobile

clients. However, it's clear that with the explosive growth of mobile clients,

new mobile connectivity options are a critical next-generation NAS feature.

"Next-gen NAS needs to offer the ability to share storage with all kinds of

users and end-point devices, including consumer devices," said Terri

McClure, a senior analyst at Milford, Mass.-based Enterprise Strategy Group

(ESG). New requirements are usually pioneered by startups and adopted by

large storage vendors much later. Startups such as Maginatics Inc. have

begun to offer products with rich end-point device support.

Page 6 of 32


Contents

NAS Need-to-Knows


scalable NAS


NAS



scale-up

Improve NAS


storage clouds

SAN Need-to-Knows


storage networking

Storage networking




with iSCSI





in popularity

Unified storage

advantages

The other aspect of accessibility is the ability of NAS systems to integrate

with applications and other systems. With the boundaries between NAS and

cloud storage blurring, and NAS systems actually powering many existing

storage clouds, next-gen NAS systems need to open themselves up and

transform from closed systems that essentially existed by themselves into

open systems that converse with other systems and applications using

standard protocols while providing versatile application integration options. In

other words, NAS systems need to become more like object stores. To start,

next-gen NAS must support cloud protocols, most importantly a REST

interface that enables HTTP-based integrations. We're now seeing NAS

vendors starting to support REST interfaces. Furthermore, NAS systems

need to support metadata beyond traditional file-system metadata to enable

applications to tag files and objects with custom information, an ability that

becomes increasingly relevant for cloud applications.

Page 7 of 32


Contents

NAS Need-to-Knows


scalable NAS


NAS



scale-up

Improve NAS


storage clouds

SAN Need-to-Knows


storage networking

Storage networking




with iSCSI





in popularity

Unified storage

advantages

NAS manageability

With petabyte file stores becoming more common and NAS systems being

used as cloud storage, manageability is a key aspect in next-gen NAS

systems. To start, the increase in human NAS management overhead needs

to grow at a much slower rate than NAS capacity growth. Despite the earlier

cited growth in the number of files (75x) and amount of information (50x) in

the next decade, IDC predicts there will only be 1.5 times the number of IT

professionals available to manage it. For this prediction to become reality,

next-generation NAS systems require management features that substitute

for the modest addition of human resources to manage substantially larger

NAS systems:

A single scale-out system where all storage is managed through a

single management pane will be indispensable

Monitoring and actionable storage analytics that provide real-time

status and metrics are a must

Automation that acts on monitoring events and analytical data based

on rules will become increasingly important

High availability that sustains multiple concurrent failures and self-

healing features will grow in relevance

As next-gen NAS systems become more open and find their way into storage

clouds, security will play a more significant role than it does today. Robust

multi-tenancy that enables secure separation and isolation of information of

different tenants on the same NAS is turning from a nice-to-have into a must-

have feature. While data is currently stored unencrypted on NAS file stores,

encryption will inevitably be a requirement, especially as mobile clients get

direct access to information on the NAS and when a NAS system is used as

cloud storage. Security tools that allow identifying and categorizing

information to be secured will be crucial to provide different levels of

protection, depending on the criticality and confidentiality of the information

residing on the NAS. Furthermore, existing threat protection devices and

fraud management systems will have to access this information.

The evolution of NAS

The accelerating growth of unstructured data, continuing virtualization of IT,

and extended file services to meet new requirements of mobile clients and

cloud computing will drive next-generation NAS features. While the ability to

cost-efficiently scale with minimal additional management overhead tops the

next-gen NAS requirements list from an IT perspective, seamless integration

with all their computing and communication devices and cloud services

matters most to end users. To get there, NAS systems need to step up and

excel in scalability, accessibility and manageability to address the needs of

an increasingly virtualized, mobile and cloud-enabled computing landscape.

Page 8 of 32


Contents

NAS Need-to-Knows


scalable NAS


NAS



scale-up

Improve NAS


storage clouds

SAN Need-to-Knows


storage networking

Storage networking




with iSCSI





in popularity

Unified storage

advantages

Scale-up vs. scale-out network-attached storage

The never-ending flood of unstructured data -- from documents and spreadsheets to photos and videos -- is driving many IT shops to pay closer attention to their file-based storage infrastructure. And, increasingly, the decision will come down to traditional scale-up vs. scale-out network-attached storage (NAS) boxes. Traditional NAS boxes have fixed capacity while scale-out NAS systems can expand to store and manage multiple petabytes of data. However, there are tradeoffs for that added scalability. Traditional NAS comprises one or two controllers, or NAS heads, and a pre-set amount of CPU, memory and drive slots. Once the NAS device reaches its limits, the user needs to buy a new, separately managed system to boost capacity and performance. Traditional NAS is sometimes known as scale-up NAS because it's upgraded by adding improved performance and capacity (speeds and feeds) to an existing architecture. In contrast, scale-out NAS grows by adding clustered nodes. These are often x86 servers with a special operating system and storage connected through an external network. Users administer the cluster as a single system and manage the data through a global namespace or distributed file system, so they don‟t have to worry about the actual physical location of the data. “Both traditional and scale-out NAS are growing, though use cases are evolving,” said Rick Villars, vice president of storage systems and executive strategies at IDC in Framingham, Mass., via email. “Traditional NAS is playing a greater role in virtualized server environments. Scale-out is the foundation for many cloud and large archive environments, and will come to dominate in terms of capacity shipped.” IDC predicts that more than 83% of the shipping capacity for enterprise storage systems will accommodate file-based data within three years, and the growth rate for file storage will be 2.5 times greater than the rate for block-based storage capacity. Enterprise Strategy Group (ESG) Inc. in Milford, Mass., forecasts that by 2015, scale-out storage will make up 80% of all net-new networked storage shipments from a revenue standpoint and 75% of all networked storage capacity. ESG doesn‟t distinguish between NAS and SAN because it assumes that all scale-out systems will ultimately support file and block storage. Traditional NAS systems increasingly have become multiprotocol. For instance, earlier this year EMC Corp. unveiled its VNX unified storage family, which converges its Celerra NAS and Clariion SAN systems. NetApp Inc.‟s

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Contents

NAS Need-to-Knows


scalable NAS


NAS



scale-up

Improve NAS


storage clouds

SAN Need-to-Knows


storage networking

Storage networking




with iSCSI





in popularity

Unified storage

advantages

FAS and V-Series products also support unified connectivity for file and block workloads. In this tutorial, we'll focus on file-storage capabilities. Here are some of the differentiators to consider when evaluating traditional NAS vs. scale-out NAS. NAS use cases Traditional NAS: File-storage covers a broad range of workloads, from office productivity and collaboration applications to specialized systems in financial services, manufacturing and health care. Vendors generally optimize scale-up NAS devices for the random access of small files, and these products work especially well with predictable performance and capacity requirements. Traditional NAS also can serve as an alternative to tape-based backup and handle limited data archiving. More recently, traditional NAS has seen an uptick in usage with virtual servers, especially those based on technology from VMware Inc., and databases, including those from Oracle Corp. Greg Schulz, founder and senior analyst at Stillwater, Minn.-based StorageIO Group, said the trend will likely accelerate now that VMware vSphere 5.0 has added greater feature/function parity between NAS and SAN with its vStorage APIs for Array Integration (VAAI) and vStorage APIs for Storage Awareness (VASA). Plus, NAS tends to be flexible and easy to use with virtualization technology, he added. Jason Blosil, a product marketing manager at NetApp, attributed the increasing interest in NAS for databases to faster 10 Gigabit Ethernet (10 GbE) networks, the lower cost of Ethernet in comparison to Fibre Channel (FC), and the ease with which file protocols configure and scale. Scale-out NAS: High-performance computing (HPC) was the original sweet spot for scale-out NAS, as select industries craved the high throughput the systems offered for exceptionally large files and data sets. Early scale-out systems were especially popular in scientific and academic research, biotechnology, oil and gas, engineering, design and media production.

HPC applications need multiple processors, memory modules and data

paths. Parallel data services, which break up single files and deliver them in

pieces in parallel, are an absolute must, said Terri McClure, a senior analyst

at ESG. She likened the services to the checkout process at a grocery store.

Systems based on parallel processing offer multiple checkout lines, rather

than funneling requests through one or two cashiers.

Page 10 of 32


Contents

NAS Need-to-Knows


scalable NAS


NAS



scale-up

Improve NAS


storage clouds

SAN Need-to-Knows


storage networking

Storage networking




with iSCSI





in popularity

Unified storage

advantages

More recently, use cases for scale-out NAS have expanded to cloud

services, Big Data analytics, and traditional data center workloads such as

high-scale home directories and file consolidation.

Patrick Osborne, manager of worldwide NAS business development at

Hewlett-Packard (HP) Co., noted his company has seen a significant trend in

archiving and data retention for compliance/regulatory purposes, as well as

business analytics. In these instances, scale-out network-attached storage

can be especially helpful with massive amounts of unstructured data.

To accommodate the expansion in use cases, scale-out NAS vendors have

to adapt their systems to handle both large files in need of high throughput

and small files requiring high IOPS.

On the low end, vendors such as Dell Inc. are trying to make a case that

scale-out NAS can be economically feasible for small-scale and remote

office/branch office (ROBO) customers.

“Traditionally, we‟ve seen scale-out NAS mainly on high-end, vertically

focused and high-performance workloads or where massive capacity and

performance were needed,” wrote Mike Davis, Dell‟s director of NAS

marketing, in an email. “We‟re focused on bringing scale-out NAS to the

masses.”

NAS options: Pros and cons of scale-out and scale-up

Enterprise IT shops coping with the explosive growth of unstructured data

need to consider their NAS options and decide whether traditional fixed-

capacity NAS devices or the emerging scale-out NAS systems will better

meet their file-storage needs.

To help make your decision, here‟s a summary of the pros and cons for the

two types of NAS systems.

TRADITIONAL NAS: PROS

One of the main attractions of traditional NAS is its simplicity. The systems

are easy to install, configure, manage and operate, especially in

environments of modest scale. Product upgrades in this “scale-up” category

follow the traditional speeds and feeds pattern of replacing a box with faster

processors and larger-capacity storage.

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Contents

NAS Need-to-Knows


scalable NAS


NAS



scale-up

Improve NAS


storage clouds

SAN Need-to-Knows


storage networking

Storage networking




with iSCSI





in popularity

Unified storage

advantages

Scale-up products are generally mature and have plenty of features and add-

on software for data protection, business continuance and storage efficiency.

Options include snapshots, one-to-many and many-to-one replication,

remote replication and remote snapshots, thin provisioning, deduplication

and compression.

Traditional NAS systems can be cost-effective and reliable, particularly for

small- to medium-sized businesses (SMBs). They help to consolidate file

servers and centralize data protection. They may also be tightly integrated

with common business applications and their native management consoles.

TRADITIONAL NAS: CONS

The main downside of traditional NAS is its inability to scale beyond the limits

of the system, forcing customers to purchase additional, separately managed

boxes when they need to add capacity. Capacity on these NAS boxes may

be underutilized if users aren‟t able to add capacity because they‟ve run out

of performance or bandwidth.

As IT shops buy multiple products, NAS sprawl is a common problem, and

the stove-piped systems have an adverse impact on floor space, power and

cooling, and tend to complicate storage management.

“It becomes a nightmare managing 25, 30, 50, 100, 200 of these individual

NAS boxes,” said Arun Taneja, founder and consulting analyst at Taneja

Group in Hopkinton, Mass. “Ninety percent of the administrator‟s time in

typical, traditional NAS environments is moving files from one NAS box to

another in order to load balance these boxes.”

SCALE-OUT NAS: PROS

Scale-out NAS systems carry the advantage of scaling capacity and

performance on an as-needed basis, far beyond the limits of traditional scale-

up NAS. They typically distribute data across many storage controllers, and

the systems‟ clustered architectures ensure high availability.

Early scale-out NAS gained a reputation as being tough to set up and

manage, but the difficulty varies by product. To a large degree, several

commercial products have eliminated that disadvantage. Users report that

adding a node to an EMC Corp. Isilon system, for instance, can be as easy

as pushing a button on the front panel.

Once the system is up and running, scale-out NAS brings the huge

advantage of being able to manage and move petabytes of data under a

single distributed file system and global namespace, and the systems

Page 12 of 32


Contents

NAS Need-to-Knows


scalable NAS


NAS



scale-up

Improve NAS


storage clouds

SAN Need-to-Knows


storage networking

Storage networking




with iSCSI





in popularity

Unified storage

advantages

generally support large volumes. Users, in turn, can maintain floor space

requirements, power and cooling costs, and management staff.

“Whether [the scale-out NAS systems] do that through namespace

aggregation or having a true global namespace, as long as the customer

doesn‟t have any management headaches, that‟s what counts,” said Terri

McClure, a senior analyst at Enterprise Strategy Group Inc. in Milford, Mass.

Some scale-out NAS systems increase performance and capacity

independently, while others require the scaling to take place simultaneously.

In addition, some products allow their users to upgrade and service hardware

without disrupting client access to data.

SCALE-OUT NAS: CONS

Some scale-out NAS systems carry fairly substantial licensing fees that are

tacked onto the incremental costs associated with adding equipment. Plus,

scale-out systems tend to lack the feature/functionality of well-established

scale-up NAS systems, at least at the moment.

For instance, a scale-out NAS system might offer remote replication, but only

the asynchronous variety -- not one-to-many or many-to-one functionality.

The vendor also might have optimized the system to handle large files rather

than huge numbers of small files and might not offer unified block and file

storage capability.

“They‟ve got good feature/function for the use cases that they‟ve grown up in,

but if they‟re going to expand into enterprise IT, most systems need to get

better at small-file, random-access performance, and they have to expand

their feature/function use cases,” McClure said. “They‟re getting there.”

Taneja agreed, adding, “It‟s only a question of time. It‟s happening very

quickly right now.”

However, Taneja said current claims by some scale-out NAS vendors that

they can scale I/O and throughput linearly to seemingly infinite levels,

through the addition of more than 100 or 200 nodes, is “total baloney.”

“You can put them together and they‟ll work. But you will have a declining

performance curve,” Taneja said. “The curve will be pretty linear for a while,

and then at some point in time, it‟ll start flattening and, further out, it‟s going

to actually start going down.”

Ravi Chalaka, vice president of product, solutions and channel marketing in

Hitachi Data Systems Corp.‟s BlueArc NAS Division, maintained that the

Page 13 of 32


Contents

NAS Need-to-Knows


scalable NAS


NAS



scale-up

Improve NAS


storage clouds

SAN Need-to-Knows


storage networking

Storage networking




with iSCSI





in popularity

Unified storage

advantages

future of scale-out NAS is the adoption of standards-based parallel file

systems based on NFS 4.1 to provide scalability beyond what current

systems can deliver.

Improve NAS management with private storage clouds and grid storage

Managing increasing file storage growth in network-attached storage (NAS) systems can place a serious burden on IT staffs. Learn why private storage clouds and grid storage systems can provide a cost-effective way to address NAS management. Managing multiple disparate NAS systems and the resulting file storage growth can be a real headache for data storage pros. Fortunately, technology options such as private storage clouds and grid storage systems are making NAS management easier. Private storage clouds or grid storage systems are somewhat similar to clustered NAS systems, but grid storage provides peer-to-peer clustering that enables it to provide single-image files over geographically dispersed, long-distance and cross-domain operations.

Geographic location "awareness" adds another dimension to NAS

management by centralizing control, management and access for distributed

environments. Based on access performance and/or data protection policies,

files are replicated and moved to the geographic location that best meets the

policy. Whether you have only a few remote or branch offices or hundreds,

grid storage systems or private storage clouds can make a lot of sense.

Let's take a look at some of the common pain points resulting from NAS

system proliferation and how private storage clouds or grid storage systems

can address them:

NAS management challenge Effectiveness of grid storage or

private storage clouds technology

Multi-NAS management Excellent for local and geographically

dispersed sites; exceptionally scalable

Client and application file access

management

Excellent: Policy based to meet user

and app requirements regardless of

location

http://searchstorage.techtarget.com/feature/NAS-management-improves-with-scale-out-NAS-file-virtualization-and-cloud-storage-services

http://searchstorage.techtarget.com/feature/NAS-management-improves-with-scale-out-NAS-file-virtualization-and-cloud-storage-services

Page 14 of 32


Contents

NAS Need-to-Knows


scalable NAS


NAS



scale-up

Improve NAS


storage clouds

SAN Need-to-Knows


storage networking

Storage networking




with iSCSI





in popularity

Unified storage

advantages

Storage tiering Good to excellent depending on

product, much simplified

NAS load balancing

Excellent: Goes beyond simple load

balancing taking into account

performance and locality

Data protection, replication, backup

and recovery

Excellent: Local and geographically

dispersed; exceptionally scalable

Total cost of ownership Very good with excellent payback

timeframes

There are currently two commercially available private storage cloud

systems: Bycast Inc.'s StorageGRID and EMC Corp.'s Atmos. The Bycast

StorageGRID runs on x86 nodes that sit in front of standard direct-attached

storage (DAS) or storage-area network (SAN) storage, so it can use already

installed block storage. EMC Atmos also runs on x86 nodes but can only use

its own JBOD storage. Bycast's product is a bit more mature with hundreds

of installations and OEM deals with Hewlett-Packard (HP) Co. and IBM.

Let's examine some of the advantages and disadvantages of using private

storage clouds or grid storage systems for NAS management.

Advantages of private storage clouds or grid storage systems for NAS

management

Same pros as clustered NAS (simplified management, data

protection and file access)

Same or lower cost than clustered NAS

Management of geographically dispersed locations

Distributed geographically aware access with centralized

management, protection and replication of all files

Geographically aware, policy-based file replication and movement

DAS and SAN investment protection or use of very low-cost storage

Disadvantages of private storage clouds or grid storage systems for

NAS management

Limited number of vendors with mature technology

No automated storage tiering at this time

Startup costs can be more than other technologies (but long-term

costs will likely be less)

http://searchstorage.techtarget.com/review/Bycast-Inc-StorageGRID-8

http://searchcloudstorage.techtarget.com/news/1381660/EMC-refreshes-Atmos-cloud-storage-platform

Page 15 of 32


Contents

NAS Need-to-Knows


scalable NAS


NAS



scale-up

Improve NAS


storage clouds

SAN Need-to-Knows


storage networking

Storage networking




with iSCSI





in popularity

Unified storage

advantages

FC technology still dominates enterprise storage networking

Fibre Channel (FC) will likely remain the predominant storage networking technology in enterprise IT shops for at least the next two years, despite past predictions it would give way to 10 Gigabit Ethernet (10 GbE) alternatives.

Market research firms and industry analysts disagree on the timeframe when 10 GbE-based Fibre Channel over Ethernet (FCoE), block-based iSCSI or file-based network-attached storage (NAS) might knock FC technology from its primary position in enterprise data storage networks. But they agree that the long-established FC won‟t disappear any time soon.

“Fibre Channel is safe. It‟s trusted. It‟s still a rock-solid solution. And customers aren‟t looking to rip everything out and change their protocols. Changing protocols is something that usually takes many years to happen,” said Stuart Miniman, principal research contributor at Wikibon, a community-focused research and analyst firm based in Marlborough, Mass.

FC storage networking technology enjoyed a 13% surge in revenue and 12% increase in switch port shipments from the third quarter to fourth quarter of 2011, according to South San Francisco-based Crehan Research Inc., which tracks the networking industry.

Seamus Crehan, president of Crehan Research, attributed the spike to normally strong storage sales in the fourth quarter and the release of upgraded FC director products from Brocade Communications Inc. and Cisco Systems Inc.

Brocade, the first switching vendor to ship 16 Gbps FC gear, reported that 16-gig accounted for 27% of its FC director sales in the fourth quarter. Brocade executives said the transition from 8 Gbps to 16 Gbps has been faster than any previous bandwidth bump at the same stage.

Even with the fourth-quarter spike, FC revenue was roughly flat in 2011 vs. 2010, and industry analysts don‟t expect the annual growth of FC technology to track in the double-digit range again. Projections from market research firms indicate it will show only modest growth, remain static or decline during the next two to five years.

Redwood City, Calif.-based Dell‟Oro Group Inc. predicts a compound annual growth rate of 3% for FC revenue and 2% for switch port shipments over the next five years before it hits a plateau. Casey Quillin, a senior analyst at Dell‟Oro, said he sees FCoE as a potential alternative to FC technology but not necessarily a replacement.

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“It‟s going to have a long tail, and it‟s going to continue to be the SAN [storage-area network] protocol of choice specifically when it comes to the need for speed, security and efficiency,” Quillin said.

Crehan Research forecasts FC growth this year with the impending ramp-up of servers based on Intel Corp.‟s new Xeon E5-2600 product family, the arrival of 16 Gbps products and an improving economy.

Still, Crehan foresees Fibre Channel flattening and gradually declining over the next four years, as FCoE takes some share.

Crehan predicts that FCoE switch port shipments will grow 127% in 2012, from 1.5 million to 3.4 million, and ultimately surpass Fibre Channel in switch port shipments in 2014.

“These technologies are on two totally different trajectories. One is a flattish, plateauing technology, and the other has an extremely fast growth rate,” Crehan said. But, he added, “FCoE shipments have far exceeded what people expected, and FCoE usage has probably lagged what people expected.”

Converged network adapters offer ‘FCoE ready’ capabilities

The shipment of FCoE switches and converged network adapters (CNAs) designed to run FCoE doesn‟t mean enterprise IT shops are implementing FCoE yet, much less running it end to end from their servers to storage. IT shops can also use CNAs with iSCSI or NAS over enhanced 10 GbE, which now has lossless properties to prevent the dropping of data packets.

“Some are buying CNAs as a strategic move,” said Marco Coulter, research director, storage practice at The InfoPro LLC, a New York City-based division of 451 Research. “They're getting „FCoE ready‟ at the CNA end, though they may only be using the Ethernet capability.”

InfoPro‟s recent survey of more than 150 large and midsize enterprises showed that 15% had deployed CNAs, but only 8% were using FCoE. Early FCoE adopters tend to use it only in one segment of the storage network, between the servers and top-of-rack switches, Coulter noted.

Joe Skorupa, a research vice president (VP) at Stamford, Conn.-based Gartner Inc., said the latest generation of enterprise-class servers generally ship with CNAs. For IT shops that virtualize servers, the 10 GbE-capable CNAs can help to eliminate a significant number of the ports, adapters and cables they needed with Gigabit Ethernet.

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“It just doesn‟t make sense anymore to put in 1 Gig adapters unless you know they're dedicated servers that are never going to host a virtualized workload,” Skorupa said.

Signs point to 10 GbE gaining a larger presence in storage networks, whether with FCoE, NAS or iSCSI. Although InfoPro‟s survey showed that 10 GbE was the predominant storage network backbone in just 4% of large and midsize enterprises, it also found that 31% were using 10 GbE.

Will Ethernet 'steamroll' FC technology?

From 2010 to 2011, iSCSI-based block storage revenue grew approximately 40%, from $2 billion to $2.8 billion, while NAS revenue escalated 22%, from $3.7 billion to $4.5 billion, according to Roger Cox, a VP in Gartner‟s global storage research unit. Meanwhile, revenue for FC-connected block storage increased just 2%, from $10 billion to $10.2 billion, although Fibre Channel clearly still represents the lion‟s share.

“Ethernet has been like a steamroller, and it‟s run over the top of anything it‟s ever had to go up against. The only one it hasn‟t run over so far is Fibre Channel, and over time, it will eventually engulf and devour Fibre Channel,” Gartner's Skorupa said. “But it will be more than five years [before] most data centers have the majority of their storage connections native on the array with Ethernet. There are more than $50 billion of installed Fibre Channel assets.”

On some fronts, the protocol wars are starting to cool with the introduction of products that support multiple connectivity options. For instance, QLogic Corp. last year announced adapters, switches and routers that can run 16 Gbps FC or 10 GbE from the same hardware. Another example was Brocade‟s release of a fabric adapter that combines a CNA, FC host bus adapter (HBA), and Ethernet network interface card (NIC) for simultaneous FC and Ethernet fabric connections.

“I would hope we‟re past a lot of the protocol passionistas debating over which one to use,” Wikibon's Miniman said. “The head-to-head technology vs. technology tends to be mattering less, whether you‟re running NAS, iSCSI, Fibre Channel or FCoE. The vendors are putting together solutions that make that part invisible.”

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Storage networking infrastructure trends must figure in upgrade plans

Enterprise IT shops looking to consolidate data centers and virtualize their servers will need to weigh the latest storage networking technology developments as they plot any infrastructure upgrade.

Here‟s a snapshot of the current state of data storage networking infrastructure for Fibre Channel (FC), Ethernet, Fibre Channel over Ethernet (FCoE) and InfiniBand in data centers.

Fibre Channel

Long-term roadmaps mention 64 Gbps FC, there are standards in the works for 32 Gbps FC and 16 Gbps products started shipping last year. But analysts say IT organizations are likely to mostly stick with 8 Gbps FC for at least two years when they purchase new switches and host bus adapters (HBAs).

Redwood City, Calif.-based Dell‟Oro Group Inc. noted that 8 Gbps accounted for 89% of Fibre Channel switch port shipments in 2011. The research firm projects 8 Gbps will represent 77% of FC switch shipments this year. In 2013, 8 Gbps and 16 Gbps will split the market at 50% apiece as the price premium for 16 Gbps technology starts to dissolve, according to Dell‟Oro.

But that doesn‟t mean IT shops are rushing to retire their old switches and adapters. All manner of FC technology -- from 1 Gbps to 16 Gbps -- is currently in use, and 4 Gbps remains the most prevalent line speed, according to recent TechTarget Storage Purchasing Intention surveys.

Customers tend to buy the highest speed available when they buy new infrastructure, as their aging equipment reaches end of life and the cost of the latest Fibre Channel iteration gets close to the price of the prior generation. Many skip an upgrade cycle, as, for example, Western University (previously University of Western Ontario) in London, Ontario, is doing with its move from 2 Gbps to 8 Gbps FC.

Although 16 Gbps FC is valuable with heavily virtualized environments, high-transaction databases, blade servers and solid-state storage, many IT organizations are hard-pressed to use the bandwidth they have today.

“It‟s not like you find data centers that have used up all their 8-gig bandwidth and are completely distressed because of that and need to go to 16 gig. That‟s usually not the case,” said Gene Ruth, a research director of storage

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technology at Stamford, Conn.-based Gartner Inc. “It‟s bandwidth looking for an application.”

Dean Flanders, head of informatics at the Friedrich Miescher Institute (FMI) for Biomedical Research in Basel, Switzerland, said the company uses approximately 25% of its 8 Gbps FC, and needs tend to be “bursty.” FMI runs about 60 virtual machines (VMs) per server over 8 Gbps, and it has two 8 Gbps links in an inter-switch link (ISL) trunk, giving it 16 Gbps for each fabric between two data centers.

“The setup is overkill at the moment,” Flanders wrote via email.

Kemper Porter, systems manager in the Data Services Division of Mississippi‟s Department of IT services, said the group uses two 8 Gbps Fibre Channel connections per server and a multipath driver, so it gets 16 Gbps. But he‟s seen peaks only of 3 Gbps on a few servers. The department uses FC primarily with its virtual servers.

Scott Shimomura, group manager of product marketing for data center SANs at Brocade Communications Systems Inc., claimed the financial, health care and entertainment industries see a need for more bandwidth. Brocade began rolling out 16 Gbps products last May and reported that 27% of its FC director sales in the fourth quarter of 2011 were 16-gig.

Cisco Systems Inc. declined to specify when it plans to add support for 16 Gbps. Emulex Corp. added support last year for 16 Gbps HBAs, and QLogic Corp. said OEM design qualifications are in progress.

Ethernet

Cutting-edge 40 Gigabit Ethernet (GbE) and 100 GbE products may be trickling into the storage marketplace, but most IT organizations are working on the major upgrade to 10 GbE, with new cables, adapters and switches, and potentially even a redesigned storage networking infrastructure.

“The transition from 1 Gigabit to 10 Gigabit is happening,” said Arun Taneja, founder and consulting analyst at Taneja Group in Hopkinton, Mass. “But like any of these migrations, it's happening at a slower pace than all the early voices you heard eight, nine years ago.”

Research from Milford, Mass.-based Enterprise Strategy Group (ESG) shows the top reason for moving from Gigabit Ethernet to 10 GbE is server virtualization. The need for extra bandwidth could escalate as IT shops move to servers that use Intel‟s new Xeon process E5-2600 processors, which can

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run more VMs per physical server, said Bob Laliberte, a senior analyst at ESG.

“A lot of organizations in the next few years are planning on having more than 25 VMs per physical server,” he said. “As that happens, higher throughput is going to be required to accommodate all the traffic from those virtual machines.”

Stuart Miniman, principal research contributor at Wikibon, a community-focused research and analyst firm based in Marlborough, Mass., expects adoption to increase with the embedding of 10 GbE technology in next-generation rack and tower servers. For the past couple of years, 10 GbE was mostly found in blade servers, he said.

IT shops have several options for 10 GbE adapters, including network interface cards (NICs), converged network adapters (CNAs, which can function as TCP offload engines), local-area network (LAN) on motherboard (LOM), CNA on motherboard and CNAs embedded as mezzanine cards in blade servers. Cisco, the leading 10 GbE switch vendor, announced support for 40 GbE and 100 GbE in January.

Fibre Channel over Ethernet

With standards work complete, the limitations of Fibre Channel over Ethernet have largely dissolved. IT shops can now deploy lossless 10 GbE and FCoE technology end to end, from servers to storage, with multi-hop, switch-to-switch FCoE even in the network core.

But, in practice, most early adopters still use FCoE only between their servers and top-of-rack switches, according to industry analysts. The top-of-rack switches split the IP/LAN traffic and the FC/storage-area network (SAN) traffic, with the storage traffic continuing via Fibre Channel to core switches and storage arrays.

Dell‟Oro predicts that FCoE switch port shipments will shoot up 139% this year, as revenue climbs 110%, from $437.3 million to $919.6 million. The market research firm also foresees 74% growth in revenue and 78% growth in switch port shipments for 2013. In both years, fixed-configuration switches (including top-of-rack and embedded blade server) comprise the majority, as opposed to modular chassis-based, director-level switches.

“As 10-gig adoption ramps up, FCoE is going to draft on that wave,” Wikibon's Miniman said. “FCoE isn‟t going to crush everything out there, but it‟s gaining steady adoption.”

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The main switch vendors have supported FCoE in fabric switches since 2009, but last year Cisco made available multi-hop, switch-to-switch capabilities with the addition of FCoE support for its MDS 9500 Series Multilayer Directors (8-port module) and Nexus 7000 (32-port module). Last year, Brocade made available multi-hop FCoE with its fixed-port VDX switches, but it has yet to support multi-hop FCoE in modular director-class switches.

CNAs ship in a variety of form factors, including adapter cards, mezzanine cards for blade servers and converged LAN on motherboard (cLOM).

Gartner‟s Ruth said the market may continue to lag until more full-function FCoE storage targets emerge beyond systems from vendors such as EMC Corp. and NetApp Inc.

FMI's Flanders said FCoE looked interesting, but after extensive evaluation he saw no advantage of convergence given the company‟s existing FC SAN. FMI has also used iSCSI for more than five years, but Flanders plans to phase it out because the performance and reliability can‟t match that of Fibre Channel.

“It‟s not getting as much traction as people were hoping for,” Taneja Group's Taneja said of FCoE. “Maybe it‟s just the conservative nature of the storage IT people. FCoE will probably take hold for brand-new projects, which are more tied to the unified fabric effort.”

ESG's Laliberte will be looking to see if VMware‟s certification of FCoE spurs greater adoption, a milestone he thought proved influential in the uptake of network-attached storage (NAS) and iSCSI. VMware supported only FC storage until 2010, he said.

InfiniBand

Low-latency InfiniBand still finds its greatest use as a server-to-server interconnect, especially in high-performance computing (HPC) and financial trading applications. But the technology is starting to pick up momentum in back-end storage.

Brian Sparks, senior director of marketing at Mellanox Technologies Ltd., claimed that remote direct memory access (RDMA) -- which allows server-to-server data movement without CPU involvement -- is gaining acceptance in storage. According to Sparks, data storage vendors that use InfiniBand include DataDirect Networks Inc., EMC (with Isilon), IBM (with XIV), NetApp (with LSI/Engenio) and Oracle Corp. (with ZFS, Exadata, Exalogic and Exalytics).

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Mellanox, the leading InfiniBand vendor, began supporting 14 data rate (FDR) 56 Gbps InfiniBand adapters, switches and cables last year, Sparks said.

Former No. 2 InfiniBand switch vendor QLogic sold its TrueScale InfiniBand assets to Intel Corp. earlier this year. QLogic attributed the decision to its desire to focus on converged networking, enterprise Ethernet and SAN products. Intel cited its commitment to the HPC community and its vision of fabric architectures that can achieve a quintillion computer operations per second (ExaFLOP/s) by 2018.

iSCSI performance: An expert discussion with Dennis Martin

Because of the success and widespread adoption of Fibre Channel, iSCSI

technology is often overlooked. But with 10 Gigabit Ethernet and data center

bridging technology picking up steam, the gap between iSCSI and Fibre

Channel is closing, making iSCSI a more viable alternative for handling

Ethernet storage.

In this SearchStorage.com interview, Demartek president Dennis Martin

discusses some of the latest technologies affecting iSCSI performance,

including data center bridging, iSCSI multipathing, CHAP and IPsec security,

iSCSI offload adapters and jumbo frames.

How can data center bridging improve iSCSI performance?

Dennis Martin: Data center bridging is an extension, or a collection of

extensions, of Ethernet that basically gives it some lossless characteristics.

ISCSI can run over this lossless form of Ethernet, and because Ethernet

provides a reliable connection, the performance of iSCSI is improved.

There's a lot of talk about having to choose between iSCSI and Fibre

Channel. What advantages does iSCSI have over Fibre Channel?

Martin: There are iSCSI initiators and even iSCSI targets included in some of

the operating systems, so you can [choose iSCSI] in software relatively

easily and you don't have to buy a lot of extra stuff. Certainly, if you're

running 1-gig Ethernet, iSCSI can run over that; 1-gig Ethernet isn't very

expensive, and a lot of people already have it, which is the advantage iSCSI

has over Fibre Channel.

What about the disadvantages?

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Martin: ISCSI tends to be a little bit higher in latency and very big shops

already have Fibre Channel, so it's well established. The reliability and

performance of Fibre Channel also tends to be a little bit better than iSCSI.

Fibre Channel has been running over a lossless connection for years, so

when you want high reliability and low latency, typically, you'd choose Fibre

Channel.

What kinds of applications are better served with iSCSI than Fibre

Channel?

Martin: It turns out that applications don't know the difference between iSCSI

and Fibre Channel. Since they can't tell the difference, the best thing to do is

figure out what you need. If you need very little latency, and lots of scalability

and nodes in the network, you might go with Fibre Channel. If you don't need

the low latency and need something a little simpler, then you could go with

iSCSI. But again, the applications can't tell the difference.

How difficult is it to manage iSCSI multipathing, and are there any tools

out there that can make it easier?

Martin: There are tools available. Most operating systems can handle

multipath I/O (MPIO). Microsoft is MPIO, and there's MPxIO [the name of the

MPIO function in Solaris], but in either case there's sort of generic

multipathing that uses a single iSCSI session and you can have multiple

addresses on the initiator, the target or both. That comes with the OS and is

fairly straightforward. Some iSCSI targets support what's called multiple

connections, so you can use a different sort of method to log in and then

accomplish the multipathing using this multiple connection option. Typically,

multiple connections and things like MPIO are mutually exclusive -- you have

to pick one or the other. The fact that you can choose it is dependent on what

the target supports.

Moving onto security, are the Challenge-Handshake Authentication

Protocol (CHAP) and Internet Protocol Security (IPsec) the only two

iSCSI security measures to know about or are there others?

Martin: CHAP and IPsec are the only iSCSI security measures I know of,

and they can certainly handle a lot of things within iSCSI itself. You can also

do other forms of encryption with the Ethernet connection. And there are

other things you can do with data at rest and the storage side. There are a lot

of other places you can do encryption, but CHAP and IPsec are the only

ones I know of that are iSCSI-specific.

You tested iSCSI offload adapters in your 2011 iSCSI deployment guide.

What kind of applications benefit from using this technology?

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Martin: The principle of the iSCSI offload is that all of the iSCSI protocol and

also the TCP/IP stack are offloaded to the card, into the adapter. It's for

anything that needs a little bit tighter latency, but more importantly it drops

the CPU utilization. Whenever you want to load up more things on your CPU,

either more virtual machines, bigger applications or whatever, that would be

the best benefit for using an iSCSI offload adapter.

What kind of advantages in iSCSI performance do you get from running

jumbo frames? In what situations is it best to use them?

Martin: Jumbo frames give you more payload per transmission. Typically,

jumbo frames run about 9,000 bytes, give or take a little bit for the headers,

but 9,000 bytes is the most common. If you're running 10 GbE, a lot of the 10

GbE equipment defaults to jumbo frames, so you sort of get that for free.

When you run it on 1 GbE, you do see a performance bump -- we've seen

10%, 20% and maybe more. If you want to get less congestion on the

network, you use the bigger packets.

What are some best practices for handling iSCSI traffic?

Martin: Although iSCSI runs on Ethernet and pretty much everyone has

Ethernet, the best practice is to run your iSCSI traffic on a separate network

or at least a separate virtual LAN. That's because iSCSI puts a different kind

of a traffic load on there. It's just better to keep iSCSI traffic separate

because you don't want it to make more collisions on your regular network

than you already have.

At the 1 GbE level, you can use separate network interface cards [NICs]. If

you go to 10 GbE, you don't have to break it up quite as much because it‟s a

much bigger pipe. Certainly, you should use server-class network adapters

for iSCSI. Don't try desktop NICs just because they're cheaper; they can't

handle all the extra features iSCSI would like to use, including Receive-Side

Scaling (RSS), partial offload functions like TCP and UDP checksum offload,

Large Send Offload (LSO) and Large Receive Offload. It's not quite the full

iSCSI, but there are some TCP offload subfunctions you can get, so you

want to have an adapter that can do all that.

If you're concerned about security on the network, you certainly want to use

CHAP, either one-way or mutual. And you want to use nonblocking switches.

There are always a few other things you can do, like use MPIO, which we

talked about already. If you're in an enterprise environment, you want to go

high availability, so you have redundant adapters and that sort of thing if you

want to get to the higher end.

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Getting started with an iSCSI storage system: An iSCSI primer

More small- and medium-sized businesses (SMBs) are discovering iSCSI is

a good fit for their organizations. In this iSCSI primer, learn about what you

need to get started with your first iSCSI storage system.

Some of iSCSI's popularity in SMBs has to do with server virtualization. And,

right now, fault tolerance for virtualization hosts is a big factor that is pushing

smaller shops into checking out iSCSI. In a virtual data center, it's imperative

to prevent host servers from failing. If a host server were to fail, it would take

all of the virtual machines (VMs) residing on it down, too. Since a single host

server can contain a dozen or more VMs, a host server failure typically

results in a major outage.

So what does this have to do with iSCSI storage systems? Well, to prevent

the types of outages that I just described, many organizations cluster their

virtualization hosts. That way, if a failure were to occur, the virtual machines

can continue to run on an alternate host. Although there are a variety of host

clustering technologies, host clustering typically requires the use of a shared

storage pool that is accessible to all of the hosts within the cluster. The

shared storage pool isn't connected to the cluster nodes through a disk

controller. Instead, the cluster nodes communicate with the storage pool over

the network through the use of the iSCSI protocol.

Hardware requirements for iSCSI storage systems

The only firm hardware requirement for using iSCSI is that there must be

TCP/IP connectivity between the remote storage pool and the computer that

needs to connect to it. Beyond that, it is widely considered to be a best

practice to route iSCSI traffic over a dedicated, high-speed network

connection so that iSCSI traffic won't be delayed by other network traffic, but

this is not an absolute requirement. If you use a dedicated network

connection (which I highly recommend), then you should use as high of a

connection speed as possible. Using faster network connections between

your server and your storage pool means lower latency, which is important,

especially for I/O intensive applications.

Software requirements for iSCSI storage systems

To establish iSCSI connectivity, you are going to need a special type of

software. The iSCSI storage array is usually a collection of disk resources

that is physically attached to a Windows or a Linux server. This server runs

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iSCSI target software. Just as the shared storage pool requires specialized

software, so does the server that connects to it. To establish a connection to

an iSCSI target, a server must run an iSCSI initiator.

Establishing iSCSI connectivity

Once you have the iSCSI initiator and the iSCSI target software, the next

step is to establish iSCSI connectivity. The exact procedure varies depending

on the software that you are using. However, these are the five basic steps

that are usually required:

1. Configure the iSCSI target to make disk resources available as iSCSI

storage. On a Windows Storage Server, this means you must create a virtual

hard drive and associate it with a specific iSCSI target (you can create

multiple targets on a single storage server). When you run the iSCSI initiator,

the software will assign the server an iSCSI Qualified Name (IQN).

2. Document this name and configure the iSCSI target to allow connectivity

from that IQN.

3. Configure any firewalls between the server and the shared storage pool to

allow iSCSI traffic to pass. iSCSI traffic usually flows over port 3260.

4. Provide the iSCSI initiator with the IP address of the Fully Qualified

Domain Name (FQDN) of the iSCSI target.

5. Establish connectivity to the storage pool and map a drive letter.

Setting up an iSCSI storage system is nowhere near as complex a task as

some people make it out to be. If you would like to learn more, Microsoft has

an excellent article at Jose Barret's Blog.

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Understanding unified storage architecture

In part one of his Storage Decisions Q&A interview, Evaluator Group senior strategist Randy Kerns outlines two ways to build a unified storage system and explains the differences between converged, unified and integrated data storage products. What makes a storage system unified? How do we define unified storage? Kerns: It depends on who you talk to, but the way we like to talk about it with our clients in the IT world is by saying, 'It's a system that can do both block and file in the same system. It will meet the demands for applications that require block access, plus all of the file-based applications and typical user home directories you have.' Does that mean all unified systems are architected in the same way? Kerns: No. Two primary approaches have been taken. One is to integrate the capabilities so that block and file are equivalent. They work through the same physical controller, and that's a very effective and economical way of doing it. Then there are other approaches that will take a block storage system and put what, in effect, is a network-attached storage [NAS] controller or a NAS head in front of it. They'll package it as unified storage, even though it's two separate systems that have been put together. Both can be very effective, and both have strengths and weaknesses. Typically, the combined solution can be a little bit more economical, but the packaged solution may have opportunities to do some different caching, for example, of the data. What are the criteria for evaluating unified storage architecture? Kerns: Ultimately, it's what you want to accomplish and what you're trying to do with that system. For the most part, you're combining the resource platform, if you will, for block and file, and then you're providing that information to users or your applications. Some people look at it as a way to centralize administration of the storage platform. Some systems have the capability of having a single administrative interface, while others may require two different interfaces. What's the difference between unified, converged and integrated storage systems? Kerns: [The answer depends on] who you talk to. Some vendors try to run with a particular word and build a case and a particular identity around the name. Unified storage has been relatively successful and fairly well identified, I think, in the user community. Converged storage is still a little

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misunderstood -- maybe misrepresented -- but converged is where you can get the server and the storage together on a single platform, and that's generally what it means, although not always the case depending on which vendor you talk to. That's the way most IT people understand it. Integrated storage can mean a couple of different things. It can mean the same thing as converged or something like an appliance where you have a prepackaged offering that has the application and storage together.

File-based growth increases popularity of unified storage systems

In part two of his Storage Decisions Q&A interview, Evaluator Group senior strategist Randy Kerns explains why the complexity of managing block and file systems separately is driving the adoption of unified storage systems.

What are the pros and cons of adopting unified storage systems? Kerns: Typically, we see [people using it] in environments that are in the smaller enterprise or midsized business [category], and they want to add in a file-based storage [array] where they may not have had it before. They were using just typical servers, running a file system on the server. They want network-attached storage [NAS], but still have a demand for block storage and want to have it in a single footprint, if you will, so they can consolidate two different systems or expand -- not add another complete system. Getting a unified system may be perfect for them; they'll now have one box that can do everything to fit their needs. That's the usual way we see people acquire unified storage. Is there a way to know when a unified storage system isn't necessary? Kerns: You can always go with two different systems. What we find is that as you move higher in the enterprise, particularly in the enterprise data center, you'll find that NAS with file-based storage is typically administered separately, and maybe has different people managing it than those managing block-based storage. [In part, that‟s because] NAS is growing much faster than block-based storage. They'll buy a NAS system specifically to meet that demand with a new project. Typically, we see higher in the enterprise that they have two separate systems -- but it's whatever works for your particular customer. When you move down market, though, you see the footprint and administration becoming more of a concern, and unified storage gets into the mix earlier on. Unified storage isn't a new idea, so why have we been hearing so much about it recently?

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Contents

NAS Need-to-Knows


scalable NAS


NAS



scale-up

Improve NAS


storage clouds

SAN Need-to-Knows


storage networking

Storage networking




with iSCSI





in popularity

Unified storage

advantages

Kerns: There's been a lot of excellent vendor promotion and they've done a good job of conditioning the market and getting people to think about it. The growth in file-based storage has also brought the issue up significantly. People are realizing, 'I need to address this. How am I going to do it?' The NAS system is the best way to do it. Then you ask, 'How can I get a NAS system to meet this combination of block and file?' Most storage systems today have enough capacity and performance to manage both, so getting a consolidated system, in many instances, is warranted. If people look at a [unified storage system] -- the availability, awareness and growth in file-based storage is what's driving [the technology].

Unified storage systems offer cost savings and management advantages

A handful of recent unified storage systems offerings have grabbed the attention of industry experts and data storage managers who believe that a single foundation for managing block, file and object data is especially appealing as virtual server environments and the cloud force storage pros to look for consolidation and standardization wherever possible. "By only having to buy a single storage system, there are capital savings involved," said Ben Woo, managing director at Neuralytix Inc., a New York City-based strategy consultancy specializing in the information industry. "When managing one system rather than two, there are operational savings to be had. Ultimately, the simplicity of having everything in a single unit makes sense for many businesses." In this video whiteboard presentation, Woo outlines the key architectural points and benefits of unified storage systems. "On the SAN side, you should think about block protocols that go down the wire -- ones and zeroes,” he said. “On the NAS side, you should think about files. Typically, they're a group of blocks, which is represented in a Word or Excel document." For storage administrators, unified storage holds the appeal of cutting workloads -- sometimes by half, Woo said. For major storage vendors, approaches to unified storage systems vary. "What you'll see with unified storage is that IT vendors come at this in two different ways," he noted. You have the integrated approach, where a single unified storage system will have both the SAN component and the NAS component together under one operating system. Alternatively, they may consider a more modular approach in which there's a NAS gateway or a NAS "head" that front ends a traditional SAN storage system.

http://searchstorage.techtarget.com/video/Unified-storage-systems-offer-cost-savings-and-management-advantages

Page 30 of 32


Contents

NAS Need-to-Knows


scalable NAS


NAS



scale-up

Improve NAS


storage clouds

SAN Need-to-Knows


storage networking

Storage networking




with iSCSI





in popularity

Unified storage

advantages

The latter is what Woo calls a modular approach to unified storage systems. "On the integrated side, NetApp is a prime example of this particular approach. However, from a modular perspective, we see companies like EMC, HP, IBM, Dell and Oracle," he noted.

Page 31 of 32


Contents

NAS Need-to-Knows


scalable NAS


NAS



scale-up

Improve NAS


storage clouds

SAN Need-to-Knows


storage networking

Storage networking




with iSCSI





in popularity

Unified storage

advantages

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