PBS Changing the Channel to iSCSI

PBS has found that an iSCSI implementation can be an inexpensive way to augment, rather than replace, a Fibre Channel SAN.

As one of the nations most established television entities, PBS is known for broadcasting cutting-edge programs. As shown by its internal use of the nascent iSCSI standard, the broadcaster is just as cutting-edge when it comes to technology.

When faced with the challenge of improving data availability on a nonprofit budget, Ken Walters, senior director of enterprise platforms at the Public Broadcasting Service, chose to leverage iSCSI technology in conjunction with an existing investment in Fibre Channel SANs (storage area networks). The move to iSCSI enabled PBS to bypass cost-prohibitive direct Fibre Channel attachment and tie non-mission-critical servers and development servers to its SAN.

By going with iSCSI and deploying a storage solution on the Windows platform, Walters estimates that he saved 50 percent over what he would have paid to expand the Fibre Channel SAN. Along with reducing costs, PBS has also improved data availability and centralized storage. "We were running out of storage space and saw the handwriting on the wall," said Walters, in Alexandria, Va. "We needed to do things as economically as possible, and iSCSI has enabled us to really maximize our existing investments."

During an on-site evaluation, eWEEK Labs was impressed by the data availability and cost savings PBS has seen since its deployment of iSCSI technology earlier this year.

Ratified as a standard by the Internet Engineering Task Force in February, iSCSI enables block-level storage traffic over IP networks, providing an alternative to Fibre Channel for building SANs.

While the networking protocol has been in development since 2000, Microsoft Corp.s introduction in June of iSCSI drivers has fueled a move to advanced external storage capabilities on the Windows platform.

To deal with mission-critical applications, PBS uses a Fibre Channel SAN anchored by an IBM 2105 Shark server, an IBM 3552 FAStT500 array and an IBM Total Storage NAS 300G G26 cluster. PBS Fibre Channel SAN supports Tier 1 (mission-critical) servers containing 3 terabytes of data.

PBS, however, has a growing number of non-mission-critical servers—including Web servers—that were not attached to the Fibre Channel SAN. Although the Web servers might not be mission-critical in the strictest definition of the term, they are certainly important for serving 150,000-plus Web pages to more than 1 million visitors per year to www.pbs.org.

Case file

  • Company Public Broadcasting Service
  • Location Alexandria, Va.
  • Challenge Decrease storage costs and improve data availability while maximizing PBS existing investment in Fibre Channel SANs
  • Solution Use iSCSI technology with the Fibre Channel SAN environment to provide real-time management and optimization of storage assets; use iSCSI SANs to support Tier 2, Tier 3 and development servers
  • Tools StoneFly Networks Inc.s Storage Concentrator i1500FS; Microsoft Corp.s Windows 2000, Windows 2000 Advanced Server, Exchange and SQL Server; Sun Microsystems Inc.s Solaris and E420 servers; Red Hat Inc.s Red Hat Linux; IBMs 2105 Shark, NAS and 3552 FAStT500 array
  • Whats next Continue to use iSCSI to consolidate storage; move away from direct-attached storage to save money; migrate to StoneFlys i3000 concentrator to take advantage of asynchronous mirroring

Source: eWEEK reporting

As content for the Web site grew, Walters knew he needed to find a way to ensure that data on those stranded servers would be stored and managed efficiently. "There was an explosion of 1U [1.75-inch] servers, and to dual-attach 50 servers to the SAN is ridiculously expensive," Walters said. "This meant critical data wasnt being stored or managed efficiently because everything was still server-attached."

Last year, Walters began developing a storage consolidation strategy for PBS. After considering direct attachment to the Fibre Channel SAN, Walters decided to leverage iSCSI technology, which he said he believed would provide the most open, scalable and cost-effective solution.

Walters began to beta test the Microsoft iSCSI initiator earlier this year. In June, he deployed Microsofts iSCSI Software Initiator 1.01 with standard Intel Corp. Gigabit Ethernet NICs on IBM BladeCenter blade servers (which have limited internal storage and expensive SAN attachment options). To anchor the IP SAN environment, Walters deployed two Storage Concentrator i1500FS systems from StoneFly Networks Inc. to provide real-time management, storage provisioning, virtualization and management capabilities.


See the Labs review of StoneFlys Storage Concentrator i3000.

The production iSCSI environment comprises Windows 2000 Advanced Servers connected to the StoneFly Storage Concentrators over a Gigabit Ethernet network. It is used to run applications such as Microsofts SQL Server 2000 and Exchange 2000, as well as Oracle Corp.s databases. Files are stored on the IBM FAStT500 modular array.

In its test environment, PBS is also using storage from its IBM Shark system. Altogether, as much as 52GB of iSCSI storage is being served through PBS Fibre Channel arrays and the StoneFly concentrators.

Walters is in the process of deploying StoneFlys Storage Concentrator i3000, which will play a pivotal role in PBS data recovery scenario. The i3000 will let him provide data replication capabilities to a secondary location and increase the availability of critical data. Walters estimates it would cost hundreds of thousands of dollars to attain traditional remote data replication functionality if the current architecture were replicated off-site.

Walters also plans to use the newer appliance to tie his mix of Sun Microsystems Inc., Hewlett-Packard Co. and Linux servers to the centralized SAN storage environment. By doing so, he said he hopes to significantly reduce management costs while again taking advantage of his Fibre Channel investment.

"Its been very refreshing to take a leading-edge technology such as iSCSI and have it integrate well into our Fibre Channel SAN," Walters said. "Ive achieved my goal of finding an inexpensive way to quickly attach non-mission-critical servers to centralized storage."

Senior Writer Anne Chen can be reached at anne_chen@ziffdavis.com.