Nationwide's San will provide back-up and disaster recovery facilities to meet the Basel II banking security regulations for 800 servers and 40Tbytes of data. It was due to be completed by the end of the year but director of technology Francis Walsh said the completion date would now be early 2004.
Walsh said, "The time we have taken has been longer than expected but we did not want to rush the job." A step-by-step approach meant it was easier to track and eliminate problems in the implementation, he added.
With its existing San nearing the end of its supported life, Hewlett-Packard began implementing the Cisco-based network for Nationwide in April.
The San will link two datacentres in Wiltshire and Northamptonshire with up to 320gbps of bandwidth using dense wavelength division multiplexing (DWDM) technology.
One datacentre will provide storage and back-up for day-to-day building society activities, the other will offer disaster recovery. The San will support 13,000 employees at 700 branches.
The first datacentre is currently running as a development environment to test the San. The network in the second datacentre has been put in place without being attached to its storage devices so that the configuration can be finalised as lessons are learned from the tests.
Once Nationwide is satisfied that both datacentres are correctly set up, they will be connected to each other and the corporate network.
Eric Sheppard, research manager at IDC, said, "It sounds like Nationwide has adopted a good methodology. With a San of that size, where a huge percentage of the business is dependent on it, you need to take time."
San technology differs from storage attached directly to servers by having storage arrays held on a dedicated network linked to the main network. A San is much more efficient than direct-attached storage, which is more difficult to manage and puts heavy demands on network resources.
At Nationwide, Cisco MDS9000s provide switching for the mainly EMC disc and tape San arrays. Cisco ONS15540 switches direct traffic across the DWDM link between the datacentres. DWDM high-bandwidth fibre optic cabling enables a single cable to provide up to 32 channels of 10gbps each.