During the past two years, Joe Wright did everything he could to consolidate Nationwide Building Society's 600TB storage infrastructure: He chose one storage vendor, backed up to one data center, replicated to one disaster recovery site and created a single storage-area network.

But Wright, a senior technology consultant at Swindon, England-based Nationwide, said as many as four full-time employees were still needed to manage data replication for disaster recovery at the $10.4 billion savings and loan.

To fix that problem, over the past six months Nationwide has been rolling out a network-based replication system that will eventually provide continuous data protection.

The latest system uses Cisco Systems Inc. switches and a replication appliance from Kashya Inc. that cost Nationwide more than $1 million, but "not millions" of dollars, Wright said. The replication capabilities have been implemented and have already cut Nationwide's administrative overhead to one full-time worker, Wright said.

"The network can see everything. You can use a single replication solution. It's been very simple to manage," he said.

The problem wasn't obvious two years ago when Nationwide installed an infrastructure based on Symmetrix arrays from EMC Corp.

But as the bank sought to cut storage costs by using EMC Clariion midrange arrays, the data replication woes worsened considerably. The different models were based on distinct architectures, requiring that backup and replication be managed separately using different EMC software tools.

At that point, Wright said, he calculated that Nationwide would need four or five software systems to replicate between Symmetrix DMX arrays and then cross-platform to Clariion.

Such management and replication issues are not unique to Nationwide, said Gartner Inc. analyst Adam Couture. The complexity of managing Clariion and Symmetrix arrays in a single environment is a common complaint among EMC users, he said.

All-Cisco infrastructure
Wright said he decided about six months ago to take advantage of an all-Cisco storage switch infrastructure, installed in the savings and loan over the past two years, to create network-based data replication.

Nationwide has 2,500 Fibre Channel switch ports on Cisco MDS 9509 director-class switches. The switches have a special line card that can host applications, such as backup and replication; assist applications running on appliances; or be used as a network accelerator.

The data replication appliance from San Jose-based Kashya works with the MDS switches.

The Kashya KBX5000 CDP appliance -- which consists of Kashya's software running on an IBM xSeries server -- replicates data between disparate arrays and can store together all changed data and the time it was changed, enabling immediate recovery to any point in time.

Any data changes that take place on Nationwide's 600 servers automatically pass through the MDS switches, which then split the data path and send one copy of the data to local storage arrays in the main data center and another copy to the Kashya appliance. The Kashya appliance then vaults that data to the disaster recovery site, which is 110 miles away. The Kashya appliance replicates to both Symmetrix and Clariion based on policies.

Managing replication through a single screen is "a far simpler solution to manage than with host-based technology," said Wright. "There was a fair amount of overhead associated with setting up each host [for replication].

"The next phase is to look at doing continuous data protection early next year," he added. "I'm starting work on that next month."