NAS. SAN. RAID. iSCSI. If you’re considering a more sophisticated storage strategy, you may be puzzled by all the choices out there. If you currently have direct-attached storage, one of the most cost-effective ways of taking your storage to the next level is to network it through network-attached storage (NAS).
Whereas direct-attached storage (storage that is directly connected to a server by connectivity media such as parallel SCSI cables) means you have islands of storage unconnected to one another — making central management complex and expensive — NAS allows you to pool your disk resources, giving you greater availability, greater scalability and a lot more control, says Alan Freedman, research manager of infrastructure hardware with IDC Canada in Toronto. This means you can restrict or grant access to users based on company policies.
NAS is networked, centralized storage that is connected to the local area network and allows multiple users to access it. A storage area network (SAN) is a separate storage network that runs on Fibre Channel. You can have both, or one or the other, depending on your resources and the type of data you’re storing. Typically, NAS is lower-priced than a SAN, but there are more SAN products coming onto the market for SMBs, Freedman says.
A channel partner or consultant can help you assess your storage requirements. Will your environment work better with NAS or SAN or with a converged solution? How much latency can you deal with? What are your disaster recovery issues?
When considering NAS, the first question you should ask is whether you share a lot of data between multiple users in the office, says Ajay Gupta, general manager of Sabio Storage in San Diego, Calif., whose Sabio CM-4 NAS solution is small enough for businesses with no IT department to manage it. Then consider how much data you have, and if that data is likely to grow (as it would continually, for example, at a doctor’s office). Or you may have legal requirements that compel you to maintain data for long periods of time.
Look for a product that’s easy to set up, configure and maintain. At the same time, find one that will allow you to drill down into more detailed features, should you require them. “You want something you can connect and configure and then basically leave alone and deal with on an as-needed basis — and hopefully not too frequently,” says Gupta. Whether you should have RAID (redundant array of independent disks) technology is another consideration. RAID is synonymous with recoverability, so if a disk drive fails, you won’t lose all of your data.
Most SMB customers are deploying NAS simply as a file and print solution for networked storage, says Parag Suri, category business manager with HP’s StorageWorks Division in Mississauga, Ont. But you can do a lot more with NAS, including disk-based backup and adding SAN functionality to your storage solution.
With NAS, users can save their work on the network drive rather than on the C: drive, which means the network becomes your primary storage location. Now you don’t have to worry about backup and recovery, because it’s already protected in a centralized location.
NAS and SAN functionality are also starting to converge in one box, says Suri, as enhancements to the iSCSI protocol allow for Fibre Channel services to be available over Ethernet. (Traditionally SANs have been based on Fibre Channel, but iSCSI SANs run over an IP network.) What does this mean? Customers can get SAN-type functionality in their NAS solution by using an iSCSI feature pack, says Suri. You don’t need Fibre Channel; your NAS simply sits on the local area network using Ethernet.
“The investment is low and can be deployed quickly and they don’t need to learn new technology like Fibre Channel topology and protocols,” he says. “They can continue using Ethernet,” Suri says.
Not only does this provide customers with more choice, it also allows them to retain their legacy infrastructure. If you have a NAS investment and you’re looking at SAN, you don’t have to rip and replace; rather, you can have a mixed environment.
But don’t take a piecemeal approach to storage, cautions Suri. Look at your entire infrastructure, your entire data centre, and take a holistic approach. This is your chance to realize the benefits of common management tools and tighter integration of products, saving yourself a lot of additional cost, complexity and confusion in the process.
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