Cutting data costs

When Nationwide was looking to consolidate its servers to cope with increasing data storage costs, it turned to fibre channel...

When Nationwide was looking to consolidate its servers to cope with increasing data storage costs, it turned to fibre channel technology and storage area networks to deliver a cheap and efficient solution, writes Julia Vowler.

Nationwide Building Society has undergone a total revamp of its IT infrastructure as part of a company-wide IT consolidation exercise. The three elements of the project were the company's servers, communications and storage facilities, which each have both unique and overlapping business drivers.

For storage the business drivers were clear. Like many organisations, Nationwide is experiencing a huge growth in the volume of data. As a large financial institution it is also affected by regulatory legislation, such as Basel 2, which increases the amount of information the business is required to generate and store.

The development of online banking has had a dramatic effect on data volumes. Nationwide was the first to offer online banking in the UK in 1997, says Arthur Amos, head of IT support at Nationwide. Whether banking is conducted over the internet or by phone it means more transactions more of the time - and they all need recording. "A customer can do three or four transactions in an evening rather than queue up in a branch," says Amos.

As well as storing data from its 10 million customers, Nationwide wanted to scrutinise and evaluate the data to understand its customers, develop its product offerings and improve customer relationship management.

Nationwide currently has 150Tbytes of stored data. "The amount of data is increasing by 50% to 100% a year, but the cost of storage is not coming down at the same rate," says Amos. "So we had to move some data to slower, low-cost, low-tier storage."

Deciding which data can be lower tier is crucial. "For many applications it is immaterial if some data is fractions of seconds slower, but for some it is critical," says Amos. "For real-time applications, such as internet banking or monitoring money laundering, speed is critical - you need real-time data. But if you are simply retrieving an old e-mail you can wait five seconds."

However, the issue of data availability can be a lot less fine-grained than tolerating a five-second delay. The worst risk any organisation can face is being unable to conduct any business at all.

"There are studies that show that if businesses are out of operation for two weeks, many will not recover," says Amos. "Disaster recover typically keeps the hardware and software going, but if the data at the disaster recovery site is not the same as at the primary site, you cannot continue business seamlessly."

What Nationwide wanted was the ability to provide synchronous mirroring, where data at the production and the disaster recovery site were exactly the same, all the time. It used EMC's Symmetrix Remote Data Facility, which removed reliance on tape back-up.

Nationwide operates its IT across two sites: one in Northamptonshire and the other in Wiltshire, dating back to when the society merged with the Anglia Building Society in the 1980s. The distance between the two sites made synchronous mirroring unfeasible. Moreover, the cost of relocating the Northants back-up site to the primary Wiltshire site was considered too high.

What made real-time storage disaster recovery a possibility was the emergence of fibre channel technology to provide high-speed links between the two sites. Based on Cisco Dense Wave Division Multiplexing technology, implemented by Fibrenet, the two datacentres are now linked via a 174km fibre network running along railway lines.

Ten of Nationwide's applications will get synchronous mirroring, including, says Amos, treasury operations, customer management, the intranet and personal loans.

Because storage is essentially an infrastructure investment, like all such spending it can be difficult to assign a straightforward return on investment metric.

"It is not at the top of business users' lists," says Amos. "As business users do not yet see a problem, it can be difficult for them to see why money needs to be spent. You have to get intelligent buy-in. You are replacing less efficient ways of working with more efficient ways. We want to be able to continue our work, but with greater volumes and as cheaply as possible. We are future-proofing ourselves."

Trying to contain storage costs in the face of flourishing data volumes is increasingly vital. According to analyst firm Gartner, storage costs are currently running at about 12% of datacentre costs. This will double to 26% in the next three years.

The ROI figures from the project are clear. Opting for a fibre connection between the two sites rather than relocating to one had a definite financial advantage. "We have saved tens of millions of pounds," says Amos.

The new storage architecture   

In consolidated architecture, storage moves away from being attached to one server and one application towards a central resource over a network - typically a storage area network - to a lower number of servers each carrying more applications. 

Nationwide installed a San before it started on its consolidation exercise, and the EMC San has been upgraded to cope with an IT architecture that consists "of more business systems running on a relatively smaller number of servers, but in a more complex environment. We are consolidating from about 50 small two- and four-way servers to a Unisys ES7000 server," says Arthur Amos, head of IT support at the building society. 

"We are turning to San-enabled storage so we can get optimum use out of our storage across all our applications. We can use all the EMC disc arrays right across the host platforms." 

The new San is designed to support real-time data disaster recovery, providing synchronous mirroring via fibre channel of all data between Nationwide's production datacentre in Wiltshire and the equivalent San at its back-up site in Northants.  

The San uses EMC's Symmetrix Remote Data Facility disc arrays to replicate data between the sites across the new dedicated Dense Wave Division Multiplexer link. DWDM supports up to 32 two-gigabits per second channels - each of which can be further divided to create more communication links - on a single fibre pair. 

Within each site, the upgraded San now uses Cisco MDS 9509 Director switches, so that any host can connect to any storage. Each Symmetrix on the San can support more than 1,000 servers.  "It increases our any-to-any flexibility without having to re-cable, improves reliability and reduces the number of connections into the EMC kit," says Amos.

Drivers for the storage project   

To increase capacity as data volumes increase because of online banking, to manage changing regulatory requirements and improve customer analysis 

To manage costs, balancing between slower, cheaper storage for less critical data and faster, more expensive storage for real-time applications 

To provide a consolidated network storage architecture to match the consolidated server architecture 

To provide synchronous mirroring across two geographically distant sites, not only to provide real-time disaster recovery, but to also to remove the necessity to relocate to one site.

This article is part of Computer Weekly's special report on storage produced in association with Hitachi Data Systems

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