Practical Skills: best strategy for Optical Fiber Channel switching Environment (1)

If the company decides to deploy an optical fiber channel storage area network (SAN), then it should determine the supplier of the switch, because it is unwise to mix different brands.

Fiber Channel switches need to communicate and cooperate with each other to manage the entire network. To ensure that the switches communicate well with each other, the best way is to select one of the three top switch suppliers and then choose its products: brocade, Cisco, and QLogic.

"(Between vswitches) communications need to follow standards, but such standards are relatively weak and uncommon for the features required to build a SAN ." Gartner analyst Robert Passmore said, "All switch suppliers have a set of dedicated and robust management functions ."

The following lists the best practices that are applicable to the optical fiber channel switching environment.

Planning considerations

Plan the SAN Based on your needs for the next three years.

Plan your future needs based on the number of applications, physical servers, and storage used in the past two years. Consider which new technologies may be deployed, such as virtual servers. Think carefully about the impact of different components on the overall environment.

"No matter what you need in the next three years, you will double this need and build it based on this goal ." Marc Staimer, president of Dragon Slayer Consulting, said: "The cost of doing so has increased, but it will make your future life much easier ."

Having no prior SAN planning is like a "great nightmare". Stapler points out that "the more well planned, the less rework ".

Determine the application throughput and I/O, so as to design the SAN Environment Scale, this can achieve the best results.

Dan Iacono, a senior SAN system engineer from HP's multi-vendor system engineering team, believes that most users are not familiar with application throughput and I/O. Unix and Windows built-in performance tools, or performance tools provided by network, SAN, and storage vendors, help compute throughput and I/O.

Understanding the application and its throughput helps determine which port (oversubscribed or full throughput) is most appropriate, and how to design a SAN to make the most effective use of network bandwidth. Many users choose the core/edge design. The Edge adopts 16 or 32-port switches and connects to a larger pilot-level switch through the internal link (ISL) of the switch.

Iacono said: "You Need To Know the throughput of the edge switch and connect it to the guide through an appropriate amount of ISL ." Reduce the number of ISL, and release the port of the switch to invest more money in the SAN.

Companies with sophisticated SAN may find that they need to directly connect applications with medium-and high-throughput edge switches to the Guide, reducing transit and getting close access to applications and storage.

Do not be afraid of over-subscription.

Most servers do not need the full network bandwidth of the Fiber Channel switch. Therefore, it is very common to oversubscribe or allocate storage that exceeds the processing capacity of the switch, because statistically speaking, it is impossible to require all storage at the same time.

Howard Goldstein, president of Howard Goldstein Associates, still believes that the Administrator "is easy to be very conservative, but not necessarily ". He also pointed out that in most SAN environments, "You only use a 10th capacity of the switch port ".

Evaluate power consumption and cooling requirements in advance.

Technical vendors often integrate products into software packages as small as possible, but the customer site may not be able to handle them. Mario Blandini, product sales director of the Infrastructure classification department of brocade data center, believes that most proposals will face power consumption problems.

"You may be curious about how many IT environments do not need additional power ." Blandini said, "Most (hospital or university) buildings were built 75 or even-years ago. These buildings are designed to consume 10,000 of electricity, and may never have imagined that 19 square inches of space would consume ."