Originating Author: Gina Geisel
Interface Choices
A typical networked storage environment consists of application hosts, storage devices, external hardware interfaces within the application server, the appropriate cabling, and a switch between the hosts and storage systems.
The external interface technologies, as components of these environments, are the foundation of the overall storage framework’s performance, scalability, reliability, technical complexity, and cost. The industry has developed several interface options to support environments such as these, including Serial Attached SCSI (SAS), Fibre Channel (FC) protocol, and Internet Protocol SCSI (iSCSI). Each of these interfaces has its own distinct features and characteristics. This article examines the benefits, positioning, target markets, applications, and special considerations of the FC storage environment.
Fibre Channel Interface Overview
FC offers increased flexibility for storage configurations with true network operation and increased scalability. With development started in 1988, ANSI standard approval in 1994, and volume deployment beginning in 1998, FC is the mature solution for data-intensive and high-speed networking applications.
FC is currently the most commonly deployed SAN (Storage Area Network) technology. While the benefits of SAN have been long apparent, it was only with the advent of FC that massive adoption of SANs became feasible.
Positioning
The FC host interface retains dominance in high-compute environments based on several key characteristics of the technology:
- Scalability – FC is a highly addressable interface capable of supporting up to a maximum of 16 million addresses. From single point-to-point gigabit links to integrated organizations with hundreds of hosts, FC delivers unmatched configuration scalability.
- Performance – With current 4 Gb/s throughput and a solid performance roadmap, FC supports the relentless growth of data and the ever-increasing reliance on quick access to it. FC is specifically designed for high performance operations with congestion-free and credit-based flow control delivering data as fast as the destination buffer is able to receive it.
- Mature and proven technology – With development going back to 1988, FC is a long-standing, highly-trusted interface technology. With its time-proven designs, FC has become a standard technology for the high performance enterprise data center.
- Investment protection with auto-negotiating link speeds – Auto-negotiable FC link speeds allow for seamless integration into an existing 1 Gb/s or 2 Gb/s environment and allow organizations to immediately benefit from the performance improvements when the rest of the configuration is upgraded.
- Cabling distance – FC can reach up to 10,000 meters maximum cabling length between discrete devices.
Target Markets
The target market for the FC interface option is primarily the enterprise data center and high-compute environments based on:
- Current market dominance – FC SANs currently dominate enterprise storage markets and are expected to retain dominance with the continual investment in FC equipment. This investment is good for complex SANs with a large number of addresses and long cabling distances.
- High performance – With 24/7 information on-demand environments, the enterprise has come to rely on FC to deliver high performance.
- Mature and time-proven designs – FC delivers the most reliable and robust configurations, which this technology has succeeded in for well over a decade. This success has created a strong and loyal following of FC technology.
- High addressability – FC can support thousands of hosts, which is typical of a growing enterprise environment.
Another market where FC technology is prevalent is at college and university campuses. This is primarily due to high bandwidth. With its high throughput and ability to achieve distances of up to 10,000 meters between devices, FC is ideally suited for college campuses. As an example, according to William Souder, Director of IT and CISO at Berry College, "I'm a Fibre Channel bigot. It gives me the connectivity, performance and scalability to meet the needs of our virtualized campus environment."
Applications
The FC interface option is highly versatile and can be used in a number of beneficial ways:
- High cluster computing – FC takes the fullest advantage of server clusters with 4, 8, or 16 hosts and up to 100 or more hosts as needed.
- Mission-critical and transaction-based databases – FC supports large, heterogeneous block data transfers reliably and will benefit applications, such as online transaction processing (OLTP), by ensuring high availability and continuous access to data.
- Virtualization – FC works well in virtual environments, as virtual machines rely on the shared storage benefits of a SAN so virtual server images, applications, and data can be consolidated.
- Streaming video – Large-block I/O applications, such as world-class broadcasting, rich media storage networks, content creation, modeling, and publishing, will benefit from the additional bandwidth that 4 Gb/s FC offers.
- Data mining – With FC, companies can accelerate and scale simulation, visualization, modeling, and rendering applications simply and easily to accelerate large dataset I/O rates, as well as cost-effectively scale and share information across the organization for high-level collaboration.
- Database in memory – High throughput and IOPs are necessary to run very large datasets in memory. Loading or refreshing drives becomes a time-critical effort. FC speeds of 4 Gb/s can be used effectively for this application because data can be loaded from the storage system to the host quickly.
- Data warehousing – To be effective, data warehousing must achieve both high bandwidth and random performance. Offering the highest levels of performance in both throughput and IOPS, FC is ideally suited for this application, delivering the information that data warehouse users need when they need it.
- Backup and restore – With the ability to rapidly transfer data from storage system to host or restore data from online backup media, FC supports short backup windows and recovery time for high productivity.
- Campus area replication – When replicating data across a high-speed SAN, data can be mirrored synchronously, ensuring that remote sites have the exact same data as the local site at all times.
Action Item: FC will retain its market dominance and be the preferred interface of choice for some time to come. This is not only based on its key advantages, such as performance, scalability and reliability, but also due to its maturity. As a technology that has been available to the market for a considerable amount of time, a large installed base of FC SANs have been implemented and many organizations will continue to build on these existing FC implementations. While there are other feasible interface options available today, if you currently have a FC infrastructure, it is important to consider why and what would be the investment needs and risk associated with converting to another interface technology. And if you are considering FC for the first time, you may see FC-based equipment become more cost competitive as well as simpler administration in order to become more competitive with the advent of new interface technologies. Therefore, this may be an opportune time to consider a first FC SAN purchase. Whichever you current state, FC should be highly considered for your next storage consolidation project.
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