Managing the information that drives the enterprise

also:

Storageessential guide

SearchStorage.co.uk

NAS: Your options

NAS systems range from standalone desktop boxes to huge clusters that scale for capacity and performance and deliver billions of files from parallel file

systems. Find out what you need in our top-to-bottom guide to the NAS market.

� what the future

holds for nas

� scale-out nas

� traditional nas

� scale-out vs traditional

� desktop nas

2 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

The present NAS market: What does it hold for the future?let’s look at the nas market to see what type of nas is right for you, and how that will change in the coming years.

editorial * antony adshead

ThiS ESSENTiAl GuidE is a great starting point for evaluating the mar-ket and deciding what type of NAS is right for you. I’ll run through the key areas we cover and suggest some technology changes I think we’ll see in the coming years.

In this guide we divide the NAS market into three key levels.Firstly, there is the high-end NAS market. This is characterised

by the use of scale-out or clustered systems. These stretch to ca-pacities in the tens of petabytes with massive throughput levels and parallel file systems that provide access to all files on all con-nected device nodes in the cluster. Crucially also, adding nodes adds processing power and/or disk capacity. This end of the mar-ket is driven by the need to store huge amounts of files, including virtual machine images, as well as the need for rapid access that multiplies to IOPS rates in the hundreds of thousands per second

3 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

as nodes are added. Next are the entry-level and medium-sized traditional NAS prod-

ucts. These can run to capacities of several hundred terabytes but do not have scale-out capabilities, so there’s the risk of running up against the limits of processing power or memory; the file sys-tems of these arrays typically don’t span multiple units so you may end up with siloed file systems in each device. That said, there’s a healthy NAS midmarket and vendors often include advanced fea-tures such as forms of repli-cation and block access via iSCSI, which effectively makes many of these products multi-protocol storage.

Finally, there is desktop NAS, which is really just the smallest capacity and perfor-mance end of the tradition-al NAS market. These devices are aimed at small businesses and larger ones that need local storage in an office or remote location. And here again vendors are providing features that were once only found in enterprise devices.

Also, strictly speaking, part of the NAS world is HPC (high-perfor-mance computing) storage, which also deals in very large amounts of files and extremely high performance but that’s outside the scope of this guide. You can read about it here though.

Those are pretty much the main contours of NAS technology at present, with two things that stand out that indicate future direc-tions of development.

The first is rise of scale-out capability, which is something that ought to become commonplace in devices at all levels of the NAS market. There seem to me to be good reasons to do so. Even if cus-tomers aren’t demanding it yet, it should be a selling point for NAS vendors. After all, scale-out capabilities allow customers to add

Vendors often include advanced features such as forms of replication and block access via iSCSI.

4 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

further units that build capacity and performance, while simulta-neously providing an easier-to-manage cluster of file storage rath-er than a collection of siloed devices, each requiring individual ad-ministrative attention.

At present it’s only the high end that does scale-out, but it’s a feature built into controller operating systems that should be por-table to devices down the range. If I was a customer for mid-range NAS I’d want to know why I wasn’t being allowed to build on my investment as I added further hardware from a vendor to my estate.

The second thing is the likely development of cleverer ways of providing better performance. At present NAS performance is largely enhanced by buying bigger trad NAS boxes or adding pro-cessing power and throughput with the addition of nodes in clus-tered NAS configurations. But, there may well be more efficient ways to speed access times and throughput rates.

In the SAN world we’re seeing some newcomers do interesting things that combine flash, spinning disk and sometimes data de-duplication. The principle here is to put the most used data on the fastest storage media and shift data between those different tiers; Tintri, NexGen and Nutanix do this, for example.

NetApp applied the idea of using a flash cache for the most used data in a NAS filer some time ago. Now Avere has taken that principle and applied flash caching to hot data across numerous NAS devices. It’s a fairly lonely furrow, but it could be a taste of things to come. n

Antony Adshead is bureau chief of SearchStorage.co.UK.

5 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

Product roundup: Scale-out NAS meets unstructured data challengewe examine how scale-out nas products from eMc isilon and netapp have been updated since last year and delve into other vendors that offer products in that space. by chris evans

IN 2011, SearchStorage.co.UK looked at the scale-out NAS market and how the major players are implementing that technology.

Products from EMC Isilon and NetApp have been updated since then and other companies now offer products in the scale-out NAS space: HDS/BlueArc, Avere, Panasas and Oracle.

EMC enhanced its Isilon scale-out NAS platform with 3 TB enter-prise-class hard drives and now provides up to 15 PB of capacity in a single Isilon file system.

And in June 2011, EMC Isilon announced it had submitted bench-mark tests to the Standard Performance Evaluation Corp (SPEC) that demonstrated NFS performance of 1.1 million IOPS and CIFS performance of 1.6 million IOPS. The configuration was based on a 140-node cluster of Isilon S200 arrays with 864 TB of storage.

Not to be outdone, NetApp followed up in early November of

6 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

2011 by submitting a benchmark test to SPEC with a 24-node clus-ter deployment of FAS6240 arrays in Data Ontap 8 Cluster Mode with 1.51 million IOPS. This performance was achieved with only 574 TB of storage capacity. For some vendors, being the “fastest” seems to be important to demonstrate their scalability credentials.

Since then, however, Avere said it has leapfrogged NetApp with a result of 1.56 million IOPS on the same SPEC test.

NetApp has also upgraded Data Ontap to Version 8.1. This has added a number of storage efficiency features to Data Ontap’s cluster mode, including block-level deduplication, flash cache, cloning and SnapMirror asynchronous mirroring. Scale-out block access has also been added, but the fundamental issues with Net- App’s scale-out model that limit its file system size have not been addressed. Users must also still decide between Version 8.1 or so-called 7-mode—ie, non-clustered—at install.

BlueArc Set for A ScAle-out NAS MArket BooSt froM HDSBlueArc was founded in 1998 in the UK. Hitachi Data Systems has sold BlueArc NAS through an OEM deal since 2006, and it acquired BlueArc in September 2011 for $600 million. BlueArc takes a differ-ent approach to high-performance scale-out NAS by using dedicat-ed field-programmable gate arrays (FPGAs) within its architecture to deliver very high scalability and capacity within a single node. Unlike commodity CPUs, FPGAs are customisable to specific tasks and can be configured to run different processes concurrently.

BlueArc’s Titan Series can scale to 16 PB within a single namespace, with 20 Gbps performance in an eight-node cluster. The use of dedicated hardware chips differentiates BlueArc from other vendors in the market today. Most manufacturers have cho-sen to build their solutions using “commodity” hardware compo-nents, such as Intel Xeon processors.

Now that HDS owns BlueArc, industry observers expect it to

7 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

accelerate its sales and the development of technology by add-ing more resources than BlueArc could afford as an independent company.

Avere SySteMS SpeeDS up exiStiNg NAS fArMSAvere Systems attacks the scale-out NAS market from a different angle. It produces a series of storage appliances that accelerate the performance of existing NAS deployments within an organisa-tion.

Avere’s FXT-series appliances use DRAM, NVRAM (non-volatile RAM) and either solid-state drives or traditional hard disk drives to provide cached access to the most active data within an existing NAS farm.

Typically, in many organisations the working set of active data within a NAS cluster can be as low as 10% of overall capacity. So, Avere focuses its appliances at delivering access to that working set, while allowing the majority of the data to sit on cheaper tradi-tional NAS products.

Besides delivering a single namespace, Avere FXT appliances can automatically tier data and deliver WAN caching. Organisations that operate from multiple disparate locations, where an appliance provides local access to data, have made use of these appliances.

The FXT series can scale to a maximum of 50 nodes, with the high-end FXT 4500 providing 144 GB of DRAM, 2 GB of NVRAM and 3 TB of SSD.

pANASAS’ BlADe ApproAcHPanasas delivers scale-out NAS using a blade architecture. Its Ac-tiveStor product family consists of director blades that manage file I/O and storage blades that provide storage capacity. As many as 11 blades can be deployed in a single shelf in a number of configura-

8 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

tions, depending on the requirements for capacity or performance.A single Panasas namespace can scale to 10 shelves per rack

and up to 10 racks. This gives a maximum capacity of 6 PB (using 3 TB drives) with 150 gigabytes per second throughput.

Panasas has taken an alternative approach to managing resil-iency within its architecture. RAID is implemented at the object level rather than the disk or block of traditional systems. Data is distributed across blades and disks to deliver high resilience. In a failure scenario, data rebuilds occur at the file level, providing fast-er access to recovered data.

orAcle’S ZfS ScAleS HugelyThrough its acquisition of Sun Microsystems, Oracle offers the Sun ZFS Storage Appliances.

These appliances use the ZFS file system. Developed by Sun Mi-crosystems in 2004, ZFS (originally named Zettabyte File System) can scale to a staggering 256 quadrillion zettabytes of storage.

ZFS uses a combination of traditional storage and flash to deliver high-performance I/O for both read and write data. The high-end Oracle ZFS Storage 7420 array scales to a maximum of 1.15 PB and can be deployed in a clustered configuration.

Unstructured data is the fastest-growing type of data, and the pure NFS market will soon be challenged by object storage ven-dors, who can deliver access to their products via NFS gateways. Object storage arrays already offer higher scalability than NAS and are seen as fundamental building blocks of cloud storage. n

Chris Evans is an independent consultant with Langton Blue.

Developed by Sun Microsystems in 2004, ZFS can scale to a staggering 256 quadrillion petabytes.

9 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

T

SMB NAS product survey: Non-scale-out/clustered NAS still fills a needtraditional, non-scale-out nas still meets the needs of sMbs despite the rise of clustered alter-natives—but product categories are becoming blurred with block access. by Martin taylor

hE NAS MArkET is a truly mature market but is also a rapidly chang-ing one. Its latest iteration, clustered or scale-out NAS—which al-lows the linking of multiple NAS devices under a single file sys-tem—has risen rapidly to meet organisations’ needs to store large amounts of unstructured data. But, there is still a need for tradi-tional NAS products to meet the demands of SMB NAS use cases such as small business and departmental/branch office file serv-ing.

While higher-end NAS products have gone scale-out/clustered, SMB NAS products have in some cases evolved to offer iSCSI and Fibre Channel block access connectivity options in addition to sup-port for traditional NFS and CIFS protocols. In this they have argu-ably become multiprotocol storage subsystems, though majoring in NAS. Other products have remained true to file access and add-ed performance enhancers such as SSD.

10 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

In this article we examine some of the current offerings in the non-scale-out SMB NAS marketplace for low and midrange use cases and its benefits for organisations that want to consolidate storage.

NetApp. NetApp virtually invented the NAS product space, or at least made itself synonymous with it. Its FAS filer products can be linked together to serve files from multiple nodes, but there are se-vere limits on this capability, and so it is not a truly scale-out NAS product set. Products start at the entry-level FAS2000 range. The FAS2220, for example, offers 12 onboard disk slots, externally ex-pandable to 60, and a total capacity of 60 TB on either SAS or SATA drives with Fibre Channel, Fi-bre Channel over Ethernet (FCoE) and iSCSI connectivity as well as NFS and CIFS file access options. The hardware comes bundled with an ex-tensive range of NetApp soft-ware, including options for thin provisioning, snapshot-ting and data deduplication. Optional extras can be added, such as remote-volume mirroring. Dual controllers in the same chassis powered by the NetApp Data Ontap operating system provide failover in the event of controller failure. The range extends to include full-scale enterprise systems in the FAS6000 family via the FAS3000 midrange devices.

EMC. Last year EMC merged its Celerra NAS and Clariion SAN products into one unified storage line to face NetApp head on. The result was the VNXe product line for smaller businesses; VNX in the midrange; and the VNX Series Gateway, which is a NAS gate-way add-on for EMC SANs.

Dual controllers in the same chassis powered by NetApp Data Ontap provide failover in the event of controller failure.

11 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

There are two VNXe products that support NAS protocols and iSCSI block access. The VNXe3100 is a 2U device with a maximum of 96 SAS or nearline SAS drives, while the VNXe3300 can take 120 drives, including flash.

There are five midrange VNX devices: four in the VNX5000 series adn the higher-end VNX7500. All are dual-controller. The VNX5000 series can contain from 75 to 500 3.5-inch and 2.5-inch drives, with flash and SAS supported. The top-of-the-range VNX7500 can hold 1,000 drives. Protocols supported are NFS, CIFS, MPFS and pNFS, Fi-bre Channel, iSCSI, and FCoE. The devices also support object stor-age and have eight to 32 ports.

hP. HP’s X1000 G2 Network Storage System is slightly less fea-ture-rich than NetApp’s FAS2000 series and EMC’s NX4. Powered by Windows Storage Server 2008 R2, it offers iSCSI connectivity and can be managed by HP X1800sb G2 Network Storage Blades. The X1000 has a maximum raw capac-ity of 24 TB with either SATA or SAS drives. Its feature list also boasts file deduplication, quota manage-ment, file screening, reporting, Mi-crosoft Windows Volume Shadow Copy Service (VSS) snapshots, Win-dows Active Directory integration and Windows Distributed File System (DFS) Replication. In HP envi-ronments, administrators can make use of integration with other HP products, such as the HP BladeSystem.

iBM. IBM’s N-series system storage NAS range is provided as OEM hardware from NetApp and offers iSCSI, NAS and Fibre Chan-nel connectivity. The N3000 Express is the entry-level system of the N series and is presented as a consolidation solution for data formerly held in direct-attached storage (DAS). The rebadged

HP’s X1000 has a maximum raw capacity of 24 TB with either SATA or SAS drives.

12 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

FAS2020 unit offers SAS or SATA disk types and features the Net- App Data Ontap operating system, which manages thin provision-ing and dual-controller options for data protection. This fits into a 24 TB array, which comes as standard with the initial N3000 2U unit. The N series allows interoperability with external storage units and controllers from higher up in the range. The N series is an affordable small and medium-sized enterprise (SME) NAS solution that can be scaled up easily to an enterprise-level array with mini-mal migration pain.

dell. Dell offers a number of NAS and multiprotocol storage product families, including the NX product lines. In the NX series, the entry-level model is the tower-format NX200, which provides capacity of up to 8 TB on four hot-swappable SATA drives. Meanwhile, the NX300 is NAS protocol-only, 1U in size and provides up to 8 TB of inter-nal capacity. The NX3000 and NX3100 offer CIFS and NFS ac-cess, with optional iSCSI ac-cess on the NX3000. Both are in the 2U rack-mount format, with 24 TB of internal capacity on the NX3100 and 12 TB on the NX3000. The new PowerVault NX3600 and NX3610 are 1 GbE and 10 GbE, respectively, with file and block ac-cess. The NX3600 scales to 576 TB while a dual NX3610 configura-tion can go to 1 PB.

Nexsan. Like EMC, Nexsan has also followed in the path created by NetApp and launched its own unified storage line, in March 2012. The NST-series devices support NAS and iSCSI and use SLC flash and DRAM to accelerate performance in the company’s FASTier cache feature, introduced with the E5000 series in 2011. There are

The NX3000 and NX3100 offer CIFS and NFS access, with optional iSCSI access on the NX3000.

13 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

three products in the NST-series family: the 5100, 5300 and 5500, with maximum capacities of 93 TB, 720 TB and 1 PB, respectively. Built-in SSD capacities are 100 GB, 200 GB and 400 GB, respectively. Drive types range from 7,200 rpm SATA to 15,000 rpm SAS or SSD. Customers can start with NAS or iSCSI access and upgrade to uni-fied storage.

Overland. The SnapServer NAS range from Overland Storage is set at a similar market level to the HP X1000. It is powered by GuardianOS, developed by Adaptec, from which Overland acquired the SnapServer line in 2008. The SnapServer N2000 unit is stack-able up to six units with a maxi-mum capacity of 12 drive slots per array. The system supports either SAS or SATA drives and of-fers NFS and iSCSI connectivity options via dual 1 Gbps Ethernet ports. Snapshotting is included via Microsoft Windows VSS. Rep-lication services are an optional extra via the Snap Enterprise Data Replicator add-on.

Although not offering the extended capabilities of scale-out NAS, the SMB NAS products here still have an important role to play in SME system environments. NAS systems have evolved from being dedicated NFS/CIFS file serving solutions into products that also offer block-level storage. This extended functionality is now within the reach of SMEs and will allow them to address their data consolidation needs whilst also offering a cost-effective storage platform for virtual server environments. n

Martin Taylor is support team leader at Capita Financial Systems.

Overland’s SnapServer N2000 unit is stackable up to six units with a maximum capacity of 12 drive slots per array.

14 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

C

Clustered NAS vs traditional NAS solutionscompared with traditional nas, clustered nas offers file visibility across petabytes of storage and is hugely scalable. find out more about its advantages. by Martin Glassborow

luSTErEd NAS hAS its roots in the worlds of media and high-perfor-mance computing; these two areas have dealt with the problems of operating massively scalable storage solutions for longer than most.

Traditional NAS solutions still hark back to the earliest days of Auspex Systems and NetApp, where a NAS solution at the very ba-sic level was a server with some disk attached to it. You could add more disk and a more powerful server, but scalability was limited in terms of performance and capacity.

Traditional NAS solutions essentially comprise a single stor-age device; more than one of them may be configured in failover cluster, but scalability is limited by the amount of CPU/memory and disk that a single NAS device can make use of. In the case of failover environments, best practice places an upper limit of 50% of each server’s individual capacity to provide the space required for failover.

By contrast, clustered NAS allows horizontal scaling across a

15 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

number of devices with all of them being active and able to see all files in the cluster. This has a number of advantages:

• If your storage servers become CPU/memory-bound, you can add a device to gain processing power without adding disk.

• If you run out of storage, you can add disk that all devices can see, but you don’t have to purchase additional devices.

• A device failure is non-disruptive, and the load of the failed unit can be spread across the whole cluster.

ScAlABility BeNefitSThe special sauce in the leading clustered NAS products is a dis-tributed file system. This enables all the nodes in a cluster to see all the files in the environment; examples are OneFS from EMC-Isi-lon, General Parallel File System (GPFS) from IBM and Ibrix Fusion from Hewlett-Packard.

This ability to scale performance and capacity requirements in-dependently of each other is an important feature of most clus-tered NAS solutions. This allows more effective use of resources compared with traditional NAS, as it is no longer necessary to pur-chase new NAS devices to add capacity or to purchase storage when all that is required is more throughput at the storage server level.

Clustered NAS can carry out all traditional NAS file serving re-quirements in a more scalable manner. For example, SONAS from IBM starts at 27 TB and could be configured with just a couple of nodes. This would compare very reasonably to a traditional NAS solution.

But NAS clustering really comes into its own when you have a rapidly growing NAS estate scaling to many terabytes of storage

16 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

with a rapid growth curve and the requirement to grow non-dis-ruptively and with minimal migration effort.

In the past if growth required more NAS, you often needed to migrate existing data to the new, larger-capacity device. With clus-tered NAS the addition of extra capacity and performance does not require a data migration exercise since all storage servers can see all the data.

There’s far less effort in-volved in managing clustered NAS compared with multiple traditional NAS devices, and I have found that with clustered NAS we can manage in excess of 1 petabyte (PB) per full-time equivalent (FTE) employee.

Clustered NAS is begin-ning to make a big impact in large virtualised environments where many thousands of server images along with their data can be stored in a multi-node NAS cluster. EMC’s acquisition of Isilon will certainly drive the use of NAS clustering in VMware environments.

cluStereD NAS veNDorSWith EMC’s acquisition of Isilon at the end of 2010, HP’s acquisi-tion of Ibrix in 2009 and NetApp’s acquisition of Spinnaker in 2003, there are now a number of mature vendors in this space. And Sy-mantec has even waded into the market. The following is a break-down of these vendors’ products:

EMC. The core of Isilon’s product is the OneFS Operating Sys-tem, which scales performance in a near-linear fashion as more nodes are added, up to a maximum of 144, and can provide a ca-pacity of more than 10 PB in a single file system.

With clustered NAS, the addition of extra capacity and performance does not require a data migration exercise.

17 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

An Isilon cluster can be made up of a number of nodes that pro-vide for IOPS, sequential throughput or capacity, which allows for a great deal of flexibility in configuration.

Isilon offers automated storage tiering using an automated policy engine known as SmartPools, which also allows addition-al nodes to be added and data to be restriped across these nodes non-disruptively.

iBM. IBM built its own clustered NAS solution based on its ma-ture GPFS clustered file system and standard Lintel servers; these have been combined to produce SONAS (Scale Out Network At-tached Storage).

SONAS supports billions of files and more than 14 PB of storage in a single file system with up to 30 interface nodes and 30 storage pods able to be configured in a single SONAS cluster.

Different types of disk can be put into different pools with a pol-icy engine used to determine file placement and file migration. The policy engine can restripe data when new nodes are added. Tape can also be fully integrated as an additional pool with Tivoli Stor-age Manager, providing transparent hierarchical storage manage-ment (HSM) capabilities.

hP. HP bundled the Ibrix software it acquired with its server technology to build the X9000 Network Storage System. This comes in a number of models, including gateways that allow customers to provide their own disk but also fully integrated appliances that con-tain servers and storage. All models in the X9000 range can be com-bined into a single file system to provide up to 16 PB of file space. The X9000 supports data tiering that can move data seamlessly and without disruption onto appropriate tiers of storage.

NetApp. The results of NetApp’s Spinnaker acquisition were re-alised in the form of the Ontap 8 operating system. Ontap 8 pro-

18 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

vides a traditional NAS environment but also can be configured in cluster mode to provide a scale-out environment. This decision must be made at the install of your NetApp appliance, and current-ly there is no way of migrating between these two modes. Ontap 8 cluster mode allows up to 24 (or 12 pairs) of NetApp filers to be combined into a single cluster. Ontap 8 has probably the least in common architecturally with any of its competitors. Cluster mode only really allows each of the filers to serve one another’s file sys-tems via a single service name; there is no single global file sys-tem.

So although the global namespace could cover the full capac-ity of all of the filers combined—which is currently in excess of 40 PB—the individual file systems are limited to 100 TB. This is a seri-ous limitation in the NetApp implementation of clustered NAS as it lacks the elegance of one large file system and will require more work, including an increased data migration workload, to scale en-vironments. n

Martin Glassborow is a storage manager with a major UK-based media company and blogs under the name Storagebod.

19 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

DESkTOP NAS dEviCES offer cheap and easily configurable storage ca-pacity for small-office and branch-office use cases. Usually these devices come with basic RAID data protection and the ability to link to network directories to set security provision. But, what are the limitations of desktop NAS, and how useful is it as a backup target or for primary storage?

In this interview, SearchStorage.co.UK Bureau Chief Antony Ads-head speaks with Martin Taylor, support team leader at Capita Fi-nancial Systems, about the key characteristics of desktop NAS and the use cases it is best suited to.

What is desktop NAS and what features and levels of perfor-mance are available in this kind of hardware?To start from the base level, we’re talking about a small disk array that’s capable of RAID striping, generally only two levels, which will be RAID 10 or RAID 5 depending on the resilience that you want, with a native operating system installed on the box that acts as a

desktop NAS: What it is and what it’s good fordesktop nas devices are particularly useful for small offices and branches. in this interview, discover the key characteristics of desktop nas. by Martin taylor

20 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

broker between your clients and the file serving. Quite often, these include things like Active Directory connectors so you can interro-gate your AD for security information.

The first network-attached storage device I ever worked with was a SnapServer that had something like a 200 file share limit on it, so obviously things have come on a huge amount since then. NAS is basically transparent to users these days. There’s very little overhead for talking to your Windows network, and it’s a cheap and easy way to store files that require file service access. Obviously, if you buy something with iSCSI connectivity you can begin to host applications and databases but for the purposes of this discussion we’re talking about file serving.

If we’re talking about levels of performance in desktop NAS sys-tems, they seem to be either four- or five-drive-capable with Level 10 or Level 5 RAID. This seems to be common for most of the entry-level devices such as the [Buffalo] TeraStation.

It’s very easy to configure these devices for users. There are simply drop-down menus and you manage them via a Web inter-face. They tend to have a broker operating system on them that talks to Windows. This can be Linux-based [although] there are fla-vours of operating system that come direct from Microsoft that are attached to these devices. Again, the important thing [when configuring these devices for users] is linking into your Active Di-rectory if you’ve got that requirement.

If [you’ve got] a very small office or if you are a home user, you can put this device on your network and point your files at it and off you go; it doesn’t require any security configuration. But if [you’re in] a small-office enterprise environment where you need to define levels of security access to files, then it’s dead easy because there is nothing native on the box and you can do it all through Active Directory. You set file and folder permissions through the interface on the desktop NAS device that are dragged from your AD.

21 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

What can you use desktop NAS for, and what about its suitabil-ity for use for backup or primary storage?In the small-enterprise environment that I’m in, desktop NAS is a very cheap and easy way of gaining some space for file archi-val or email archival purposes: stuff you need quick access to [if you’re at] a small remote site. Also, image storage is a big thing with us with our large image databases, and we find they’re a very cheap way of storing large amounts of images; they are available to users all the time. And there’s redundancy in the devices so we don’t have to worry about failures, and we get alerts if there is a problem.

So, basically, they’re great as a bin area for all files that you don’t want on levels of expensive storage. It’s perfectly possible to drop files down to them off of the SAN as well, when we find it’s no longer economic to keep them there for access reasons, etc.

But mainly the use for us, at small satellite offices, they’re very cheap file storage, even cheaper than Windows storage. When you look at the price of storage on desktop NAS you’re looking at something comparable to a single server drive, so with the amount of disk space you get and the redundancy, economically desktop NAS definitely makes sense in the [small-enterprise] environment but it must be used correctly. I certainly wouldn’t consider it for live, online storage of files that required a lot of access; that would be more server-based.

The other use we find for desktop NAS in our environment is that it’s a very cheap way of hosting backup files. Currently, we’re us-ing [Symantec] Backup Exec… to back up all our stuff and find that desktop NAS is good as a backup to disk device. This is for non-crit-ical backups, incremental, etc.

With the amount of disk space you get and the redundancy, desktop NAS makes sense economically.

22 Storage Essential Guide: Your NAS options

Future of NAS

Scale-out NAS

Traditional NAS

Scale-out vs Traditional

Desktop NAS

Obviously, we hive off our full backups off to tape but [the desk-top NAS is] great as a transition area, as compared with the cost of storage such as tape the price is very favourable and because it’s online all the time, the restore times are quick. Because there aren’t any problems getting people to deal with tape loading [at] remote sites, etc, then it’s available instantaneously… if we have to restore something for users. So as a backup staging area I defi-nitely think they have a good use, and that’s the main purpose we use them for other than file storage. n

SearchStorage.co.UK

Editorial Directorrich castagna

UK Bureau Chief antony adshead

Senior Site Editorsue troy

Assistant Site Editorfrancesca sales

Creative Directorlinda koury

Publisher, Storage Media GroupJillian coffin jcoffin@techtarget.com

Senior Vice President, International bill crowley bcrowley@techtarget.com

TechTarget First Floor 3-4a Little Portland St. London, England W1W 7JB www.techtarget.com

©2012 techtarget inc. no part of this publication may be transmitted or reproduced in any form or by any means without written permission from the publisher. techtarget reprints are available through the yGs Group.

about techtarget: techtarget publishes media for information technology professionals. More than 100 focused websites enable quick access to a deep store of news, advice and analysis about the technologies, products and processes crucial to your job. our live and virtual events give you direct access to independent expert commen-tary and advice. at it knowledge exchange, our social community, you can get advice and share solutions with peers and experts.

TechTarget Storage Media Group