Fibre Channel is a high-speed data transfer protocol that delivers raw data blocks from computers, mainframes, and supercomputers to storage devices. Commercial data centers primarily use it for storage area networks (SANs).
First used in 1988, Fibre Channel was standardized through the T11 Technical Committee of the International Committee for Information Technology Standards (INCITS).
Read More about Fibre Channel
Fibre Channel got its name because it only ran over optical fiber cables. Later on, Fibre Channel was imbued with the ability to run over copper cables.
Watch this video to learn more about Fibre Channel.
To understand what Fibre Channel is better, let’s first tackle what a SAN is.
What Is a Storage Area Network?
A SAN is a specialized, high-speed network providing access to storage devices. It typically comprises hosts, switches, storage elements, and storage devices interconnected using various technologies, topologies, and protocols. It’s useful for data centers since it can span multiple sites.
Now that we’ve gotten that out of the way, let’s dive into more details about Fibre Channel.
What Are the Three Major Fibre Channel Topologies?
The three major Fibre Channel topologies are:
- Point-to-point: In this topology, two devices are directly connected to each other using N_ports, making it the simplest topology with limited connectivity and dedicated bandwidth.
- Arbitrated loop: All devices are in a loop or ring in this topology. Adding or removing a device from the loop interrupts all activities. When one device fails, the ring breaks.
- Switched Fabric: All devices are connected to Fibre Channel switches in this topology, making it conceptually similar to modern Ethernet implementations. It can accommodate tens of thousands of ports. Unlike in the arbitrated loop topology, a port failure doesn’t affect the other ports’ operation.
While the Switched Fabric topology can be likened to an Ethernet implementation, the two differ.
What Is the Difference between Fibre Channel and Ethernet?
Ethernet is designed for connecting computers within a local area network (LAN). Fibre Channel, meanwhile, is designed explicitly for block-level storage in SANs. Note, though, that Ethernet can be used for both block-level (SAN) and file-level (NAS) storage.
While Ethernet only supports asynchronous mirroring, Fibre Channel supports synchronous mirroring.
What Are the Two Types of Mirroring?
Mirroring can be synchronous or asynchronous. What’s the difference?
- Synchronous mirroring: Synchronous mirroring is a means to protect data by writing it to a remote site and a local disk simultaneously.
- Asynchronous mirroring: Asynchronous mirroring can update data in a local site immediately and in a remote site when there’s greater bandwidth.
So, organizations setting up their networks can choose between Fibre Channel and Ethernet based on what kind of mirroring their data requires.
Apart from different topologies, Fibre Channel also uses different switches.
What Kinds of Switches Does Fibre Channel Use?
Fibre Channel generally uses two kinds of switches.
- Directors: These offer a high port count in a slot-based chassis with no single point of failure, ensuring high availability.
- Switches: These are typically smaller and have a fixed configuration, making them less redundant.
What Are the Different Fibre Channel Speeds?
The original Fibre Channel had a maximum data rate of 1Gbps. Today, the standard increased this rate to 128Gbps. Note, though, that 8Gbps, 16Gbps, and 32Gbps are also used.
Why Use Fibre Channel?
Fibre Channel’s ability to support synchronous mirroring makes it crucial for organizations that require all their backups—on-premises and remote—to be updated each time changes are made to the data they store. Simply put, therefore, Fibre Channel makes for faster disaster recovery and business continuity, making it ideal for mission-critical applications—those a company can’t operate without.
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While Fibre Channel networks have proven very useful, they can be expensive to build, hard to manage, and inflexible to upgrade. Despite these challenges, though, many SANs still employ Fibre Channel.
Key Takeaways
- Fibre Channel is a high-speed data transfer protocol that delivers raw data blocks from computers, mainframes, and supercomputers to storage devices.
- Fibre Channel is ideal for SANs.
- The three major Fibre Channel topologies are point-to-point, arbitrated loop, and Switched Fabric.
- Fibre Channel primarily differs from Ethernet in that Fibre Channel supports asynchronous and synchronous mirroring while Ethernet only supports asynchronous mirroring.
- Fibre Channel uses two kinds of switches—directors and general-purpose switches.
- Fibre Channel supports speeds of between 1–128Gbps.
- Fibre Channel’s ability to support synchronous mirroring makes it crucial for organizations that require all their backups to be updated each time changes are made to the data they store. It makes for faster disaster recovery and business continuity, making it ideal for mission-critical applications—those a company can’t operate without.
