Going The Array WayDisk-Based Centralized Storage Has Become A Value Proposition For SMEsby Bruce Gain Increased email traffic, more compliance procedures, and larger file sizes add up to a perfect storm for many enterprises when it comes to storage. As the volume of data continues to grow exponentially, IT admins often struggle to effectively manage the swelling number of gigabytes to back up. Many administrators at small to midsized enterprises take a direct and easy route to boost capacity for backups by using DAS (direct attached storage). When a server's hard drive becomes full with data, you only need to add one or more disks to add capacity. However, DAS can only take you so far. Having to invest in more drives for each server can generate a lot of redundant capacity; one disk may have 100GB of free space it may never need, while another reaches its limit. The network admin also has to manage the different servers' operating systems and interfaces with DAS. The risk of data loss is significant if and when a disk fails and no data redundancy backup system is in place. Enter disk array storage, which offers a disk-based centralized repository for your network's servers. Data from various sources in your enterprise, ranging from Exchange email servers to databases, can be routinely backed up and managed with a single interface and server. You are thus able to set policies, establish backup schedules, or perform other storage management tasks for your enterprise's entire storage needs from a single location. The problems DAS poses are resolved as all servers have access to the same amount of data storage capacity with a centralized array infrastructure. "Managing storage on a server-by-server basis is difficult," says Charles Vallhonrat, manager of product marketing, Entry-Level Arrays StorageWorks, for HP (www.hp.com). "Sharing [capacity] between servers with consolidated storage offers one place to manage [storage tasks] with better utilization of capacity." Disk arrays using RAID configurations can also offer protection in case one or more of the array drives fails. Depending on the flavor of RAID used, it is possible for data to be replicated and mirrored on the different disks in the array configuration. Falling Costs Array-based storage, of course, is nothing new. Large enterprises have relied on the technology for more than a decade. "The units are designed for ease of use and durability," says Cooper Cowart, a senior director of marketing at Dot Hill Systems (www.dothill.com). "With a heritage of telco and mil-spec applications, the current family of products has been cost-reduced but have not had their reliability or usefulness compromised." Centralized array storage was expensive when it was first introduced. Larger enterprises with high-volume data-archival needs could afford to make the necessary investments when the technology first became available, while the costs were previously prohibitive for SMEs. The good news, however, is that prices have fallen. "As disk prices drop and capacities increase, disk arrays are becoming [more] attractive not only for their traditional production application but also for backup and archiving," says Jay Krone, director of storage platforms at EMC (www.emc.com). However, the infrastructure is still not cheap. "The current generation may, if anything, have an initial acquisition cost that might intimidate certain prospects," Cowart notes. "But when a total cost of ownership is calculated, the numbers fare very well against competing systems and solutions." While not all SMEs stand to benefit from array storage, its utility and falling prices at least warrant a look as a storage alternative. However, certain variables determine whether the technology is right for your enterprise. "I think that enterprise-class storage arrays are often the best options for [SMEs], depending on their actual business needs," says Michael C. Fisher, CEO of online storage provider ElephantDrive (www.elephantdrive.com). "The four key value propositions that the organizations need to evaluate are reliability, read/write speed, volume, and expandability-and they all need to be evaluated against cost. Overall, the latest technologies provide truly impressive performance across all four; they're just pretty pricey." How Safe? Array storage's reliability to safeguard your data largely comes down to the RAID disk setup you use. With RAID 0, you are in trouble if a drive fails, as data is not duplicated across disk arrays, compared to the data protection RAID 5 offers. Reliability also comes down to the disks themselves, the quality of which will determine the rate of media failures over the course of time. "The technology of [array] storage system software and hardware is extremely robust and will operate virtually indefinitely," Cowart says. "The disk media, by contrast, has a more limited life span and reliability." Meanwhile, a typical shelf-life for an array storage infrastructure, comprising disk failures, is several years. "We typically cite a design life of five-plus years, though earlier generations of this family are still in service after eight to 10 years," he adds. Setting up a SAN remains a daunting prospect for many admins. With crash-prone Windows-based servers and workstations to deal with on a daily basis, adding another element to the network might represent just more tasks to manage. But while setting up SANs in the past required a lot of time and expertise, the infrastructure has become a lot easier to set up, HP's Vallhonrat says. Indeed, Vallhonrat says a non-IT person, such as the office manager in a dentist's office, could set up and manage HP's All-in-One Storage system. But as an IT admin, you don't necessarily want storage systems to be too easy to install and administer so that your IT expertise is no longer required, either. Indeed, Vallhonrat acknowledges that customers have expressed concerns about array-storage products becoming too simplified: "This is something we have been told," he notes. The Right Combination Combining different storage systems is a good idea for many scenarios, especially for critical data backups that cannot be compromised. The data redundancy that RAID can offer is of no use if your data center is destroyed in a fire, for example. "Ideally, [array solutions] would be complemented with an online storage failsafe for business continuity purposes in the event of a disaster. Your amazing I/O speeds and expandability won't do you much good after a fire or a flood, unless you've secured that data offsite," Fisher says. "Further, selective online storage provides a useful access layer. By replicating select subsets to an online storage service, you can allow users to access key data while minimizing your exposure." |
