2.4. Overcloud Requirements

The following sections detail the requirements for individual systems and nodes in the Overcloud installation.

Note

Booting an overcloud node from the SAN (FC-AL, FCoE, iSCSI) is not yet supported.

2.4.1. Compute Node Requirements

Compute nodes are responsible for running virtual machine instances after they are launched. Compute nodes must support hardware virtualization. Compute nodes must also have enough memory and disk space to support the requirements of the virtual machine instances they host.
Processor
64-bit x86 processor with support for the Intel 64 or AMD64 CPU extensions, and the AMD-V or Intel VT hardware virtualization extensions enabled. It is recommended this processor has a minimum of 4 cores.
Memory
A minimum of 6 GB of RAM.
Add additional RAM to this requirement based on the amount of memory that you intend to make available to virtual machine instances.
Disk Space
A minimum of 40 GB of available disk space.
Network Interface Cards
A minimum of one 1 Gbps Network Interface Cards, although it is recommended to use at least two NICs in a production environment. Use additional network interface cards for bonded interfaces or to delegate tagged VLAN traffic.
Intelligent Platform Management Interface (IPMI)
Each Compute node requires IPMI functionality on the server's motherboard.

2.4.2. Controller Node Requirements

Controller nodes are responsible for hosting the core services in a RHEL OpenStack Platform environment, such as the Horizon dashboard, the back-end database server, Keystone authentication, and High Availability services.
Processor
64-bit x86 processor with support for the Intel 64 or AMD64 CPU extensions.
Memory
A minimum of 6 GB of RAM.
Disk Space
A minimum of 40 GB of available disk space.
Network Interface Cards
A minimum of 2 x 1 Gbps Network Interface Cards. Use additional network interface cards for bonded interfaces or to delegate tagged VLAN traffic.
Intelligent Platform Management Interface (IPMI)
Each Controller node requires IPMI functionality on the server's motherboard.

2.4.3. Ceph Storage Node Requirements

Ceph Storage nodes are responsible for providing object storage in a RHEL OpenStack Platform environment.
Processor
64-bit x86 processor with support for the Intel 64 or AMD64 CPU extensions.
Memory
Memory requirements depend on the amount of storage space. Ideally, use at minimum 1 GB of memory per 1 TB of hard disk space.
Disk Space
Storage requirements depends on the amount of memory. Ideally, use at minimum 1 GB of memory per 1 TB of hard disk space.
Disk Layout
The recommended Red Hat Ceph Storage node configuration requires a disk layout similar to the following:
  • /dev/sda - The root disk. The director copies the main Overcloud image to the disk.
  • /dev/sdb - The journal disk. This disk divides into partitions for Ceph OSD journals. For example, /dev/sdb1, /dev/sdb2, /dev/sdb3, and onward. The journal disk is usually a solid state drive (SSD) to aid with system performance.
  • /dev/sdc and onward - The OSD disks. Use as many disks as necessary for your storage requirements.
This guide contains the necessary instructions to map your Ceph Storage disks into the director.
Network Interface Cards
A minimum of one 1 Gbps Network Interface Cards, although it is recommended to use at least two NICs in a production environment. Use additional network interface cards for bonded interfaces or to delegate tagged VLAN traffic. It is recommended to use a 10 Gbps interface for storage node, especially if creating an OpenStack Platform environment that serves a high volume of traffic.
Intelligent Platform Management Interface (IPMI)
Each Ceph node requires IPMI functionality on the server's motherboard.

Important

The director does not create partitions on the journal disk. You must manually create these journal partitions before the Director can deploy the Ceph Storage nodes.
The Ceph Storage OSDs and journals partitions require GPT disk labels, which you also configure prior to customization. For example, use the following command on the potential Ceph Storage host to create a GPT disk label for a disk or partition: 
# parted [device] mklabel gpt