HTK supplies automated voice services for clients including O2, a number of public sector services including the police force and the Habbo social networking website. The firm has experienced exponential growth in business over the past three years and needed to create resilience in its systems.
With a production site and a single HP SAN at a separate data centre, computing and storage was completely intermixed between locations - a situation which presented risks to business continuity, says Justin Bowser, operations director with HTK.
"The context is that the business is growing quickly and we needed to separate out the functions of our two hosting sites which had always had some crossover in terms of tasks and ensure business continuity provision with one site mirroring the other," he says. "We just couldn't afford the cost in terms of revenue and reputation that any downtime would have caused and needed a resilient set up that we could rely on."
The solution implemented was an EMC Celerra NS40, which was installed at HTK's primary site. With a total capacity of 5 Terabytes split between 4TB of SAN running 15,000rpm disks and 1TB of NAS on 10,000 rpm disks, the system comprises four trays in total with two Data Mover head units.
The mixed NAS/SAN set up allows HTK to make the best of both file and block level storage, says Bowser.
"The beauty of this solution is that we can have NAS and SAN in the same physical infrastructure. For applications such as our databases which we want to associate with particular servers block-level storage is most appropriate," he says. "For voice and video NAS is more appropriate."
HTK's selection process was a two horse race between EMC and HP which took two months. HP supplies the firm's servers and its existing SAN so it was a natural candidate, while EMC was also called in. Project cost was, "nearly into a six figure sum," says Bowser, "but I managed to keep it just into five."
EMC won out on value for money, says Bowser. "For the two Data Movers that we wanted the HP equivalent was getting on for twice the cost. We were also sold by EMC's story on the ease and low cost of migrating from iSCSI to Fibre Channel at a later date."
Bowser says the investment is justified because the implementation has allowed HTK to handle volumes of personal data which had been growing month on month as well as recording of tens of millions of minutes of recordings of voice traffic. "We simply needed the ability to deal with such quantities of throughput and not worry about I/O requirements," he says.
In the past, SAN and NAS existed as separate technologies but this is changing with so-called unified storage, which combines the two. When IT departments integrated the two technologies in the past issues could arise over throughput, capacity and scalability because of controller limitations. Now manufacturers are selling systems that work more or less from the box and the market is gaining traction, says Robin Burke, research vice president with Gartner.
"Unified storage has begun to become more prevalent in recent years," he says. "Over the last four quarters I calculate that SANs have had 80% revenue market share compared to 20% for NAS/unified storage while within the NAS category 12% of the units shipped are designed for unified storage."
"Over the next few years all storage will become unified," he adds. "The advantage is that you have the best of both worlds – block storage and file level – all in one box."