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By Chris Angelini |
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Ever get the feeling that you’re falling behind the times? Whereas enterprises have a different IT staffer for Windows administration, storage management, hardware provisioning, email, database work, and so on, the VAR has to wear all of those hats-—sometimes at the same time. The catch, of course, is that many small businesses are operating under the same compliance laws as enterprises. They have their own SMB customers who need to access data around the clock, necessitating 24x7 access. According to IDC, company data is expected to grow 740% between 2006 and 2010. Keep that statistic in mind when you think about another claim from Gartner, which is that 40% of businesses suffering interruption due to data loss will fail within five years. No pressure, but your SMB customers are depending on you to keep them up and running, protected against data loss, and within the letter of the law. The Storage Landscape Yes, the need is urgent, but don’t start pulling your hair out just yet. There are a number of angles from which you could tackle the issue of small business storage. It’s worth it to take the time to make sure you really understand the concepts, terms, and strategies involved first. Many SMBs deploy Direct Attached Storage (DAS) because it’s easy and inexpensive. Especially in environments with a single server, DAS really does make sense. As the organization grows and the demand for storage increases, however, DAS becomes less and less efficient. One server might outgrow its disk capacity, so you have to add a JBOD. Never mind the server right next to it with terabytes of available space. The business gets bigger, and storage becomes increasingly distributed, even though the original idea was to centralize data. Working around the shortcomings of DAS requires an understanding of network storage. You’re probably already intimately familiar with network-attached storage (NAS). For those who aren’t, NAS is file-level storage that is connected to a computer network and provides data access to other network clients. Think of a NAS device as a file server that’s stripped down to the basics for storing information, providing access to that information, and managing both functions. NAS solutions offer SMB customers a handful of benefits. For one thing, they take you back to the idea of centralization. Instead of expanding storage space at each server, keep the business’ data on a NAS device and expand from there. The performance of a NAS device is often better as well. An SBS 2003 server, for example, is tasked with Exchange duties, SQL databases, user authentication, file serving, and often print serving. Adding NAS helps alleviate some of the processing demands.
Storage Area Networks (SANs) are a completely different monster, yet they’re still easily confused by small businesses that automatically associate SAN with expensive enterprise technology. Whereas a NAS box is essentially a file server on an existing network, SAN comprises its own network over which blocks of data are moved. Put differently, SAN consists of storage connected in a fabric easily accessed from different servers on a secondary network. Because of the way SANs transfer data, there’s no difference between SAN storage and directly attached storage from software’s point of view. SANs have a reputation for high performance. After all, the goal is to give servers access to storage that appears local but is actually centralized. The SCSI protocol is most common on storage networks, but the SCSI physical interface isn’t suited to networking, so a mapping layer is used to form a network with other protocols. Fibre Channel is one of the most popular (and most expensive). iSCSI is another; it maps SCSI over TCP/IP and delivers a cost-effective interface most SMBs are already using. Each has its benefits. Businesses that have been in the SAN game for a while probably have a Fibre Channel infrastructure in place. An incumbent technology in network storage, Fibre Channel networks run at 1 Gb/s, 2 Gb/s, 4 Gb/s, or more. As you scale up, the performance advantage over iSCSI, which is most commonly run on a 1 Gb/s Ethernet network, increases. The maturity of Fibre Channel is another compelling reason to lean in that direction, especially when you think about mission-critical storage arrays where downtime is not an option. Increasingly, iSCSI has what it takes to connect servers to SAN storage. The protocol shines most brightly in the SMB space, where its cost effectiveness and ease of implementation are certainly apparent in relation to Fibre Channel. The performance hit your customers once incurred by running iSCSI software can now be circumvented by Ethernet controllers equipped with a TCP Offload Engine. Make it a point to upsell a card such as Intel’s PRO/1000 PT Quad Port Server Adapter, which includes Intel’s I/OAT technology, load balancing across processors, and virtualization support. Why Spend On Storage? As you work your way up the storage hierarchy, performance goes up, and price follows right behind. By the time you’re pitching SAN technology to an SMB with direct-attached backup drives, your customer might be asking, “Why bother?” As the VAR, it’s your job to help that business understand the challenges tied to properly managing storage. According to Microsoft, there are five principal pillars bolstering your storage sale: scalability, fault tolerance, data protection, manageability, and cost effectiveness. Start with scalability. Your small-business customer might look at the back of his server, see four USB 2.0 ports, and think he has storage scalability covered. But tacking DAS onto a server is the wrong way to approach growth, and it’ll eventually cost more to fix down the road. You want to help centralize information so that everyone is working on the same version of a file, data is easy to locate, and backups don’t miss any current information. Even in a small business, NAS is critical if only for its organizational benefits. SAN is often better for multi-location businesses. In either application of network-based storage, providing fault tolerance is a challenge. If a transactional database server’s data resides on a SAN, the storage device and network have to be up 24x7. Mirrored enclosures, RAID arrays, and redundant servers are some of the suggestions Microsoft gives for improving the reliability of your storage solutions.
No matter how you choose to improve the uptime of a network storage solution, pulling data from the far reaches of your customer’s network and onto a NAS or SAN makes data protection and recovery much easier to manage. In an environment reliant on DAS, each server is either backed up individually or included in a network batch. That decentralization might not affect one-server shops, but as the infrastructure expands, you’ll have a harder time keeping SMBs protected. With critical data housed on a SAN, it doesn’t matter how many servers your customer uses or even where they’re located. Keep data in one place where it’s easier to protect. Network storage is also easier to manage. NAS presents a particular challenge because every NAS vendor employs its own interface. The lack of continuity between appliances means you or your customer require training on each system. If you were able to offer storage hardware based on a more familiar management console, you could cut back on the problems presented by vendor-specific applications. The ideas of scalability for the future and easier management today sound grand. The problem is that even though SMB customers need a lot of the same capabilities previously limited to enterprises, they don’t have enterprise budgets to blow on extravagant storage solutions. In other words, you need to step up to the plate with a value. Perhaps that value lies in consolidation. Install a single SAN to replace a handful of file servers, thereby saving money on hardware and licensing. Or maybe you quote a simple iSCSI SAN that can take data scattered across employee workstations and put it in one place to minimize administrative overhead. Yes, SAN technology can be affordable. Show your customer that the infrastructure is more straightforward than he might have thought, and you’re on your way toward a sale. Making An iSCSI SAN Work Let’s work under the assumption that your small-business customer is interested in networked storage and wants to hear his options. For basic file serving, NAS may very well be the way to go. However, SAN offers a more elegant way to deliver high-performance storage to the machines crunching transactional data. The traditional Fibre Channel SAN would easily start in the five-digit range, scaling up with complexity. Then you tell that customer that there’s an alternative. An iSCSI SAN would deliver many of the benefits leveraged by big iron Fibre Channel boxes at a fraction of the price. The storage layer of an iSCSI SAN is simple enough. Ideally, you’d want to encourage redundant power supplies, redundant disk controllers, and enough drives for a RAID 10 or RAID 5 array, plus a hot spare should one go down. If you go with a flexible SAS controller, mix and match SAS and SATA drives in order to hit the right balance between price and performance. Of course, the box needs its own Gigabit Ethernet controller too. Anything less and you’re just begging for lackluster network performance. Use a processor with enough horsepower to unwrap and reassemble iSCSI packets. Can you see where we’re going with this? Pick up a storage platform such as Intel’s SSR212MC2 and you’re well on your way to enterprise-class performance from hardware readily available to the SMB.
Storage in an iSCSI SAN communicates over Ethernet—-Gigabit at a bare minimum. You don’t want to run a SAN on your customer’s primary network. A SAN belongs on its own network, independent of conflicting loads. Keep that in mind and install the appropriate number of NICs or HBAs. Run cables from the server to a Gigabit switch, and then to each client. Configuration is really a breeze, which is one reason iSCSI has so much SMB appeal. Software constitutes the final, and perhaps most important, component of an SMB SAN. VARs have tons of choice when it comes to storage software. If you’re a Windows shop, Microsoft’s Windows Unified Data Storage Server (WUDSS) acts as a great example of how easy it is to configure networked storage. WUDSS comes bundled with an iSCSI Software Target snap-in that enables the storage box to connect to remote iSCSI targets—-networked servers and tape drives. The iSCSI snap-in also lets the storage server itself function as a target. You don’t need to know much about SAN technology to get the operating system up and running. Rather, Microsoft guides you through a number of initial configuration tasks at logon, specifying credentials, configuring networking, and setting up identity mapping. Once you have WUDSS set up, managing the SAN is a piece of cake. Again, configuration is enabled through a series of wizards, which create new iSCSI targets, help create virtual disks, extend existing virtual disks, and schedule disk snapshots. Tasks that would have previously required a deep knowledge of managing storage networks are condensed into guided processes, opening the door to any reseller with experience in Windows Server. SAN In Action Now that you know what’s involved in building a SAN, demonstrate the reasons for your SMB customer to invest in networked storage using real-world scenarios. Microsoft presents a handful where its WUDSS software package couples well to a hardware solution such as Intel’s SSR212MC2 storage server.
Storage consolidation is the most obvious reason to apply SAN. Connect one server running WUDSS that is attached to an iSCSI disk array to a network with other storage devices. WUDSS is able to unify the network, managing shares, permissions, disk allocation, and assignment. Think of it as a single tool you can deploy to manage storage resources from a single console. Finally, you have SAN as application support. Microsoft Exchange and SQL both rely on fast access to data, which you can deliver by clustering servers together. Windows Server 2003 boxes running Exchange, for example, are set up with iSCSI target software and connected to the network hosting WUDSS and an attached iSCSI disk array. You can carve out virtual disks on the array to host Exchange’s mail store. Do the same elsewhere on the network with a SQL box, then carve out another virtual disk for hosting its database. Add backup to the picture and you’re looking at a very elegant system that gets important information into one place while still serving it up over a high-performance network as if it were local to other machines. |
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Copyright © 2007 RAM Magazine. All rights reserved.
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