InfiniBand Part 1
RAID Recovery - InfiniBand
InfiniBand is a type of communication link used in high-performance computing (HPC). The InfiniBand architecture is based on the Virtual Interface Architecture, and it allows data flow between processors and high performing I/O devices such as storage disks. InfiniBand is highly scalable. It delivers high quality of service and failover. Because of these features, InfiniBand is used as a server-connect in HPC environments.
Features
InfiniBand transmits data in the form of packets up to 4 KB. Several such packets constitute a message. There can be different types of messages: a remote direct memory access (RDMA) read/ write message, a channel send or receive message, a reversible transaction-based operation, an atomic operation, or a multicast transmission.
Unlike Ethernet, InfiniBand is a point-to-point bidirectional serial link and uses a switched fabric topology. All transmissions begin or end with a channel adapter. InfiniBand works with the help of two types of connectors: a host channel adapter (HCA) at the processor end, and a target channel adapter (TCA) at the peripheral device end. These adapters exchange information and ensure security and quality of service.
InfiniBand supports several signaling rates. Typically serial connection’s signaling rate is 2.5 gigabit per second in each direction per connection. Additionally, it can support double and quad data speeds (5 gigabit and 10 gigabit respectively. The links can also be bonded together for yielding additional throughput and redundancy.
InfiniBand links use 8B/10B encoding; i.e., for every 10 bits of data sent, it carries 8 bits, resulting in four fifths of the original speed. Thus, a single data rate of 2.5 gigabits can carry 2 gigabits whereas a double and quad data can carry 4 and 8 gigabits respectively.
