Single disk Difference [%] FC-AL
Array Ultra ATA Array Write workload 0.98 1.5 3.16 Read workload 0.8 2.5 2.8 However, such results are not without limitation.
allows communications between a maximum of 126 nodes, but they share the total bandwidth of the loop.
The storage system supports four to ten half-height 3.5" FC-AL
disk drives as well as one or two hardware RAID controllers in a single compact 3U high rack-mountable enclosure.
The combination card's gigabit Ethernet portion is designed to give users the same performance as a standalone card, supporting both full and half-duplex interface connections, while the FC-AL
portion offers high-bandwidth storage connectivity to high-capacity storage arrays.
Fairness, especially when a shared bandwidth protocol like FC-AL
is converted to switching, must be fully understood to appreciate the performance and system level ramifications of accessing large numbers of drives by a small number of controllers.
Emerging technologies like Serial ATA (SATA) and Serial Attached SCSI (SAS) are coming alongside established Fibre Channel Arbitrated Loop (FC-AL
) for storage device level interface.
Over the past year, Fibre Channel-arbitrated loop (FC-AL
) has emerged as the high-speed, serial technology of choice for server-storage connectivity.
Adding InSpeed (basically interconnecting every FC-AL
disk tray to a Vixel "chip-switch"), arrays become a switched bunch of disks (Vixel here introduces yet another acronym: SBODs), yielding a three- to five-fold speed improvement.
A pair of modern controllers have enough combined data bus and data memory bandwidth to transfer data between six 2Gbps back-end FC-AL
buses and six 2Gbps front-end Fibre Channel fabrics at full speed, which removes internal bandwidth as a performance bottleneck.
(Fibre Channel-Arbitrated Loop) configurations incorporate redundancy and switched FC fabric provides redundancy, alternate path routing, and zoning.
While all of the servers, hubs, and storage subsystems are based on the widely supported Fibre Channel protocol known as FC-AL
, the early switch products are based on a newer protocol called "Fabric" and are positioned more for SAN backbone applications and less for storage consolidation applications.
Fibre Channel has become the industry standard interconnect with addresses for 127 devices on a single FC-AL
loop and sixteen million on a fabric with cascaded switches.