Compute nodes (recommended minimum - 4 cores)
‍64-bit x86 processor with support for the Intel 64 or AMD64 CPU extensions, and the AMD-V or Intel Virtualization (Intel VT) hardware virtualization extensions enabled;
Supports ppc64le on Power 8 or Power 9 systems running the OPAL firmware;
A minimum of 6GB of RAM (additional RAM may be required);
A minimum of 40GB of available diskspace (1TB is recommended);
2 x 1 Gbps network interface cards (at least 2 network interface cards are recommended for production environments);
Each compute node requiresintelligent platform management interface (IPMI) on server’s motherboard.

Controller nodes.
64-bit x86 processor with support for the Intel 64 or AMD64 CPU extensions;
Supports ppc64le on Power8 or Power9 systems running the OPAL firmware;
A minimum of 32GB of RAM(64GB is recommended for optimal performance);
A minimum of 40GB of available disk space;
2 x 1Gbps network interface cards.

Red Hat OpenStack Platform director.
8-core 64-bit x86 processor with support for the Intel 64 or AMD64 CPU extensions;
Red Hat Enterprise Linux as the host operating system;
A minimum of 16GB of RAM;
A minimum of 100GB of available disk space (10GB of free space is needed before attempting an overcloud deployment or update);
A minimum of 2 x 1Gbps network interface cards (10Gbps is recommended for provisioning network traffic, especially if provisioning a large number of nodes in overcloud).