Easy electronic access to information has become one of the most powerful business tools an organisation can have. As a result, many companies are amassing gargantuan volumes of data that is not only expensive to maintain, but extremely difficult to manage.
According to a March 2001 investigation by Forrester Research, storage capacity in Global 3,500 companies is growing at 52% a year and, by consequence, storage now accounts for 75% of the total hardware budget. Analysts at Gartner, meanwhile, predict that unless IT departments change their storage strategy, their costs could quadruple over the next four years, even once the falling costs of storage devices has been taken into account.
This means IT managers are increasingly being called upon to justify further investment in storage when budgets in most other areas of IT have dried up. Consultants, storage companies and analysts agree that, as with servers, consolidating islands of storage into one central location on a network can help organisations get more value from their existing – and future – storage investments.
Forrester estimates that the five-year cost of centralised networked storage for 5 terabytes (TB) of data is around $10 million, compared with $14 million for storage systems that are scattered piecemeal around an organisation, with savings on the cost of both people and the management of storage devices.
This was the case at UK publishing group Financial Times Newspapers (FTN). “We’ve dramatically reduced our storage costs,” says Alan Murphy, IT director at FTN. “Whereas before we maintained multiple copies of data across the servers, we now have just one central source. By consolidating the information, we are saving approximately £50,000 a month.”
According to Murphy, FTN did this by ridding itself of its existing, heterogeneous network of storage devices and consolidating the 11 TB of information used by its Unix and NT servers on to a single fibre-connected Symmetrix RAID (redundant array of independent disks) system from storage giant EMC. FTN has also improved how efficiently it uses its storage capacity. The Symmetrix system has a potential capacity of 70 TB, and the storage architecture provides the ability to add in extra storage servers for file serving if required.
Financial Times Newspapers’ approach to centralising storage is not the only one. Better technologies to support shared storage across a network are also emerging. For example, corporate-wide storage architectures can be based on storage area network (SAN) technology, which links servers directly to multiple storage subsystem devices via a high-speed fibre channel. According to Forrester Research, this can help reduce overall costs by as much as 30%.
Another approach is network-attached storage (NAS), where organisations simply bolt on highly-optimised file-server storage systems to their existing networks. Many companies actually favour a hybrid approach, where large volumes of files reside on a dedicated SAN, but NAS devices can handle less data-hungry applications.
Since most organisations will have a combination of storage systems – whether NAS or SAN – from a combination of different vendors, simply centralising storage onto a network does not eliminate the management issue. To get the promised benefits of reduced costs and increased capacity from networked storage, a number of storage system and software suppliers now hail ‘virtualisation’ as the most effective approach to managing a hybrid storage architecture.
Virtualisation software, proponents claim, can remove the limitations imposed by different hardware and operating systems, and create a single, flexible pool of storage that is available to all servers. However, many of the benefits of the technology have been clouded by hype, and most of the functions offered have been around for some time in standard storage management software.
Systems vendor IBM, for one, has chosen to stay away from the term ‘virtualisation’. “We’re not using the term virtualisation, because there’s no agreement in the market about what it actually means,” says Sergio Resch, IBM’s marketing manager for disk and networked storage systems in Europe, the Middle East and Africa. “There are plenty of products around today that give the server a virtual view of data. So we’re asking the customer, ‘OK, what do you mean by virtualisation?’ And we’re finding that some of them want a storage device that can connect to different operating systems, while others want management software that can glue together different storage resources.”
Jason Phippin, product manager with storage software company Veritas, takes a similarly sceptical view. “We’ve been supplying virtualisation technology for 15 years. It’s a myth that it goes hand in hand with SANs – virtual storage has been around in the data centre environment for a long time.”
One of the most well-documented benefits of storage consolidation is lower total cost of ownership. Because centralised storage is cost-effective to manage, it offers IT directors a way of reducing their storage spend. Ease of management was what mainly motivated Euroconex, the card payment processing services arm of the Bank of Ireland, to install a SAN to store data from its Windows 2000, Sun and Oracle systems.
“Data is data, wherever it resides – but a SAN gives you manageability and availability,” says Gene Budd, director of technical support at Euroconex. The company has around 1.4 TB of data from its Wicklow call centre on its existing storage network, and will be increasing this to over 2 TB when it upgrades the system over the next few months. There is minimal data stored on PCs; the combination of Windows 2000 Active Directory and central data storage on the SAN means that staff can sit down at any desk, log on, and have all their applications and data available anywhere in the organisation.
“If you compare the management it took to keep 50 to 60 servers (each with their own data stores) up and running, to the same operation under a SAN, it really makes it much easier,” says Budd. Euroconex considered opting for a lower-cost NAS system but rejected it on performance grounds. “NAS has its uses if you have a small sales office to support, but it wouldn’t have the capacity for the volumes of data we have here. SAN gives you a higher-speed network, and because it’s on its own backbone, you don’t have to worry [about the impact on the network] if someone decides to pull a huge file across,” Budd explains.
Furthermore, because management of storage can take place at the SAN level rather than at the application server level, there is no impact on servers when maintenance tasks such as back-ups are carried out.
However, a SAN will only take you so far along the route of storage optimisation, says Jean Banko, product marketing manager at Fujitsu Softek. “Many customers and prospects that I talk to thought that implementing a traditional SAN would solve all their issues, but they’re finding that it has not. They still have to have very experienced storage administrators to manage the SAN. It wasn’t until virtualisation came along that they could simplify that process,” she says.
By enabling companies to flexibly allocate space to different servers and across different storage devices, virtualisation claims to mask the complexity of the underlying storage infrastructure, allowing administrators to manage the whole architecture from a single console.
Crucially, say proponents, virtualisation also enables organisations to further improve storage utilisation. “Across the board, customers are under-utilising the storage boxes that they’ve invested in,” says Andy Norman, managing director of storage specialist Sagitta. “Virtualisation allows vastly improved capacity utilisation and improved return on investment. We’ve seen as much as a 20% improvement on capacity utilisation by use of virtualisation.”
Business services aggregator 7 Global opted to install the SANsymphony virtualisation system from Datacare in March 2001 because it wanted to allocate storage flexibly to different servers running different customer applications. “We have to support a mix of storage devices and a mix of processor types,” explains Graham Crich, 7 Global’s senior vice president of strategic partnerships. “You can get tools from IBM to manage IBM storage, or from Hitachi to manage Hitachi devices, but it’s very rare that tools will work for multiple vendors. At the time, SANsymphony was one of the few products we found that was really open; it provides an open layer to sit between the servers and the storage, enabling us to delete, create, and maintain volumes across multiple devices.”
The software enables 7 Global to make the most of its storage investment by sharing storage devices across different customers and reallocating space flexibly, says Crich.
Examples of virtualisation in practice such as this are few and far between, however. And although an increasing number of organisations are adopting a network-centric approach to storage, widespread implementation is still a long way off.
In the meantime, most companies will continue to face the day-to-day challenge of managing heterogeneous storage architectures. According to Jason Phippin at Veritas, a combination of storage technologies – including virtualisation, SANs and NAS – will allow these organisations to make the most of their storage capacity, rather than any single technology approach. “When it comes to storage, there’s no one size that fits all,” says Phippin.