Infrastructure servers are used to administer the system and provide user access. They are not typically involved in computation but provide services that are critical to the overall HPC system. These servers are used as the management nodes and login nodes. For small-sized clusters, a single physical server can provide the necessary system management functions.

Infrastructure servers can also be used to provide storage services, by using NFS. In this case, they must be configured with additional disk drives or an external storage array. One management server is mandatory for an HPC system to deploy and manage the system. If high-availability (HA) management functionality is required, two management servers are necessary. Login nodes are optional. Dell Technologies recommends one login server per 30 to 100 users.

A base configuration for Infrastructure servers that Dell Technologies recommends is:

Table 1.      Infrastructure servers base configuration

The PowerEdge R650 server is suited for this role. Typical HPC clusters only use a few infrastructure servers. Density is not a priority, but manageability is important. The Intel Xeon Silver 4314 processor, with 16 cores per socket, is a basic recommendation for this role. A more capable processor may be appropriate if the infrastructure server is used for CPU intensive tasks, such as compiling software or processing data. 256 GB of RAM provided by sixteen 16 GB DIMMs provides sufficient memory capacity, with minimal cost per GB, while also providing good memory bandwidth.

These servers are not expected to perform significant I/O, so mixed-use SATA SSDs configured with RAID 1 should be sufficient for the operating system. For small systems (four nodes or less), an Ethernet network may provide sufficient application performance. For most other systems, HDR InfiniBand is likely to be the data interconnect of choice. It provides a high-throughput, low-latency fabric for node-to-node communications, or to access Dell Technologies Validated Design Storage solutions.