Focus on Fibre Channel

Posted on November 01, 2000

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The following Q&A was excerpted from an online chat session hosted by searchstorage.com, a Web-based search engine site for storage-related articles and information (www.searchstorage.com). Questions were posted by end users.

Respondents were Skip Jones, chairman of the board, and David Deming, president, of the Fibre Channel Industry Association (www.fibrechannel.org).

What is the FCIA SANMark program, and what benefits does it offer the industry?

Deming: SANMark is a program that the FCIA designed to test for compliance to industry standards. The current level is SANMark Level 1, which directly addresses the Fibre Channel Arbitrated Loop protocol in all SAN environments, including switched topologies. This program is an ongoing effort by the FCIA and will continue to define how to test the different SAN levels, including SAN management. The program will provide numerous benefits to the industry, including quicker time to market, easier implementation and configuration, and lower development costs.

Why is interoperability so important?

Deming: Interoperability enables end users to connect components from different vendors. If all components are interoperable, end users or integrators can choose from numerous vendors, and integration is much easier. Interoperability provides hassle-free SAN installation.

When deploying Fibre Channel within a SAN/LAN environment, what performance benefits are there to the processing systems?

Jones: A key advantages of a SAN is its ability to offload valuable CPU power from a server onto a separate storage network. This keeps the data flow out of the server CPU memory path for storage-centric operations such as backup and data retrieval. The CPU is free to more efficiently process applications. Additionally, LAN bandwidth is not used to process and move storage data.

Should vendors look to SANMark and the FCIA for standards when developing SAN products?

Deming: Yes. The FCIA is the driving force behind defining interoperable SANs. Stay tuned to the FCIA web site for additional SANMark notices.

How can Fibre Channel SANs benefit the ISP, ASP, and SSP markets?

Jones: These markets probably represent Fibre Channel's fastest-growing areas of adoption because the SAN topology benefits their business. Whether it's Yahoo, Amazon.com, or AOL, ISPs generate the type of background stor-age traffic that lends itself to creating stor-age pools and offloading storage traffic from the servers. That's as compelling as Fibre Channel's scal ability benefits when adding terabytes monthly and managing the resulting complexity. Storage service providers such as StorageNetworks use Fibre Channel and SANs as their storage backbone because of the return on investment they get in networked storage performance, efficiency, reliability, manageability, and scalability required for their storage applications.

How can we make progress toward enterprise storage standards as long as some vendors decide to do their own thing (e.g., FibreAlliance and Jiro)?

Deming: Enterprise storage standards usually require providers to agree on many aspects of the SAN architecture. These agreements directly affect product design and implementation. FibreAlliance and other groups concentrate on narrowing the scope of design, allowing vendors to deliver products to market more quickly.

Now that the final layers of interoperability are in place, what are the next steps for the FCIA?

Jones: The next steps are a push for common equipment deployment, SANMark, and driving rapid market adoption of Fibre Channel SANs.

What benefits does Fibre Channel technology offer for Windows NT environments?

Jones: Fibre Channel allows a user to "zone," or partition, segments of the storage network, thereby optimizing processing efficiency.

How long has SANMark existed? What is the level of acceptance by the manufacturers?

Deming: SANMark has been in development for more than a year. All vendors are taking SANmark seriously, and I believe that all storage manufacturers support this effort.

Are there currently any benchmarks that indicate which Fibre Channel switch gives the best performance?

Jones: The FCIA's primary focus is to establish programs that promote "good citizen" behavior in a SAN. Performance benchmarks are so specific to platforms and applications that it would be difficult to provide useful benchmarks. With regard to switches, one of their key attributes is not to affect end-node network performance one way or the other, so it's unclear what a switch benchmark would test.

Which storage vendors are actively participating in the SANMark certification?

Jones: Currently, I know of no storage vendor that is not directly or indirectly (by virtue of their component suppliers) part of the SANMark program.

What are some of the benefits of employing SAN technology within a LAN environment (e.g., server-less backup)?

Jones: Users can deploy server-less backup so that near real-time backup can be done in parallel with operations with little or no robbing of processing power, thereby increasing system efficiency. A user can also have zoning capabilities. Also, the SAN operates at near-peak efficiency because intelligence is embedded within the Fibre Channel architecture, which is optimized for storage.

Will the FCIA be involved with SAN certifications?

Deming: Currently, the FCIA uses SANMark as a tool that allows vendors to develop certification programs. For now, the FCIA has no plans to be directly involved in SAN certification.

How would you recommend determining hub, switch, and peripheral interoperability, short of holding a private plugfest?

Deming: Typically, I get the products in, configure a SAN, and go for it. In a Windows environment, this includes installing drivers, running Disk Admin-istrator, determining that the storage is present, and (if present) formatting the devices. This essentially is a mini-plugfest. It has been my experience that you will be successful in mixing almost all vendors.

Does SANMark certification also cover third-party copy features for server-less backups?

Deming: At this time, SANMark does not address third-party copy. There are, however, FCIA efforts that will address this issue.

With the advances in storage over IP, or SCSI over IP, do you see a mingling of Fibre Channel and IP devices in a SAN configuration?

Jones: In fact, there is already mingling. For instance, there are numerous SAN applications that use products supporting IP over Fibre Channel. Another compelling development is the tunneling of Fibre Channel over a WAN (IP and/or leased DWDM lines) for connecting remote SANs. Efficient, scalable, high-performance storage processing mandates local SAN topologies. WANs are simply used for the interconnection between SANs, once the storage data has been processed locally.

One of the major drivers for SANs is server-less backup. What interoperability challenges will this present?

Deming: I agree that server-less backup is an important driving force behind SANs. Now that the interoperability issues behind the interconnecting infrastructure have been ironed out, the only interoperability challenges I see will be determining how the different applications will take advantage of server-less backup. q

The desire to prove interoperability is prompting vendors to demonstrate that data moves from one device to another when the SAN is healthy. But all devices have failures. Users need a heterogeneous SAN that interoperates in the real world. Shouldn't the Fibre Channel industry require that any interoperability claims also include working through a series of errors and device failures?

Deming: Good point! You have just described what is possibly the heart and soul of SANmark. It is a set of test suites for testing pre-defined behavior. SANMark is not about "demonstration" of interoperability; rather, it is a set of test suites that center around "What happens if" scenarios. The crust of the work after brief calibration of a normal "healthy SAN" is injecting errors, hot-plugging and unplugging storage units, and server and component failover. This work started at the local loop and is now being extended deep into the fabric, management services, and upper-layer protocols.

For more information, visit the FCIA's Web site: www.fibrechannel.org.

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Skip Jones
Chairman, FCIA

Click here to enlarge image

David Deming
President, FCIA


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