3.1 Red Hat Enterprise Linux  Red Hat Enterprise Linux is one of the world’s leading enterprise Linux platforms. It runs on  highly scalable, multi-core systems that support the most demanding workloads.  Collaboration between Red Hat and engineers from major hardware vendors ensures that the  operating system (OS) uses the newest hardware innovations that are available in processor  design, system architecture, and device drivers to improve performance and reduce power  utilization. For more information, see Red Hat Customer Portal. This section provides information about the device drivers that are used in this solution. This is a single Virtual Protocol Interconnect (VPI) software stack that operates across all  Mellanox network adapter solutions. The stack supports specific uplinks and Mellanox  InfiniBand Host Channel Adapters (HCAs) to servers. Mellanox OpenFabrics Enterprise Distribution (OFED) contains many important components,  for example: GLYPH<SM590000> Mellanox HCA drivers: – Includes both InfiniBand and Ethernet drivers. GLYPH<SM590000> Upper layer protocols (ULPs): – For example, IP over InfiniBand. GLYPH<SM590000> Utilities: – Diagnostic tools. – Performance tests. GLYPH<SM590000> OpenSM: InfiniBand Subnet Manager GLYPH<SM590000> Mellanox Firmware Tools (MFT) GLYPH<SM590000> Message Passing Interface (MPI): – The OpenMPI stack supports the InfiniBand, RoCE, and Ethernet interfaces. – MPI benchmark tests. GLYPH<SM590000> Adaptive Routing (AR) GLYPH<SM590000> Fast Link Fault Recovery and Notification (FLFR) GLYPH<SM590000> Free AR: No constraints on the output port selection. GLYPH<SM590000> Bounded AR: The switch does not change the output port during the same transmission  burst. This mode minimizes the appearance of out-of-order packets. 20  IBM High-Performance Computing Insights with IBM Power System AC922 Clustered Solution  Mellanox OFED supports adaptive routing (AR) management. The AR manager supports the  following advanced InfiniBand features: AR enables the switch to select the output port based on the port’s load. AR supports two  routing modes: 3.2 Device drivers  3.2.1 Mellanox OpenFabrics Enterprise Distribution