Carnival Cruise Lines sails with iSCSI

Like many enterprise IT shops, Carnival Cruise Lines relied on Fibre Channel-based storage area networks (SANs) over the past 20 years to support its 43,000 employees and dozens of ships. But, when it came time to refresh its technology, the cruise line skipped the traditional forklift upgrade of monolithic boxes in favor of an Ethernet-based, modular architecture.

This month, the cruise line finished its changeover to Internet SCSI (iSCSI) SANs running over copper wire and Ethernet and a VMware-based virtualized server infrastructure. The change has reduced its total cost of ownership for hardware, software and maintenance by 60% from its previous architecture, and greatly increased system performance through a combination of solid state disk and serial ATA hard drives in the arrays.

The company began its IT switch on land first, replacing three EMC Symmetrix arrays, four Clariion arrays and one Celerra network-attached storage server in its Miami data center with Dell /EqualLogic iSCSI arrays. It then replaced EMC arrays on 22 ships with the same iSCSI SAN technology.

Through use of iSCSI and virtualization of its server environment, the company was able to reduce its shipboard IT footprint by about 60%, reclaim about 7,000 hours per year in IS management, achieve a 38% performance improvement for its Oracle data warehouse, and meet a four-hour recovery time objective for virtual machines through SAN-based replication.

Doug Eney, vice president of IS engineering, said the decision to move to an Ethernet-based storage architecture was relatively simple after a free test bed set up by Dell demonstrated it could exceed the company's performance needs.

"We saw the performance and the cost and it was for a fraction of what we were getting from other vendors," Eney said. "Dell was being very aggressive with the cost [of hardware] and in the software engineering side as well. They were not only pricing out the cost of a car, but pricing out the car with all the options as well."

Onboard each of its ships, Carnival set up three Dell PowerEdge R710 servers running VMware's vSphere and Unix, Windows or Linux operating systems all attached to a single Dell/EqualLogic PS6000-series iSCSI SAN. Prior to the upgrade, each ship ran between 13 and 22 physical servers, with direct- attached storage in support.

The Dell/EqualLogic arrays run vStorage API integration with VMware vSphere, which automatically migrates data from SSD to SATA hard drives based on preset performance requirements.

Carnival storage architect Robert Torres said there was initially some concern that iSCSI running on 10Gbit/sec. Ethernet couldn't maintain the throughput required to support the company's Oracle 10g data warehouse.

"We drive a lot of data, about 600MB a second or 11,000 IOPS. We were able to not only achieve that but surpass that ... without stress. We have a lot of room for overhead and growth," he said.

Torres said he sees Carnival as a trend follower when it comes to its deployment of iSCSI technology, and he's watched more and more enterprises embrace the technology. Torres said one reason many enterprises may have dragged their feet in deploying iSCSI technology is because it's been associated with small and medium-sized business in the past, but he said he's confident that it can handle all but the most demanding performance requirements. For example, Carnival continues to use its Symmetrix arrays for its fiber-attached mainframe.

"I don't think we invented the wheel here. It's being driven by cost savings," he said.

Liz Conner, a senior research analyst for Storage Systems at research firm IDC agrees. According to Conner, iSCSI SAN deployments have increased 41.4% in 2010 over the previous year and NAS grew 49.8% year-over-year.

"The increased investment by end users and vendors alike in [iSCSI] has helped fuel the overall growth [of storage], while easing budget constraints sparking a pickup in [Fibre Channel] SAN and higher end systems alike," she said in a statement.

One of the reasons iSCSI has gained popularity is because of its ability to use commodity Ethernet switches instead of more expensive Fibre Channel switches. Using iSCSI also eliminates the need for host bus adapters on application servers, which are also costly.

"It does require an integrated IT organization - that the networking group and the storage group work well together, which really gives you cost savings too because you're utilizing the intellectual property of your people better, too. But now you have common core switches. The cost of that network connectivity really goes down," Eney said. "There's no reason having FUD going into this."

Lucas Mearian covers storage, disaster recovery and business continuity, financial services infrastructure and health care IT for Computerworld. Follow Lucas on Twitter at @lucasmearian or subscribe to Lucas's RSS feed . His e-mail address is lmearian@computerworld.com .

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