openstack-ansible/deploy-guide/source/overview-requirements.rst

Installation requirements and recommendations

This section describes software requirements, hardware recommendations, and network recommendations for running OpenStack in a production environment.

Software requirements

Ensure that all hosts within an OpenStack-Ansible (OSA) environment meet the following minimum requirements:

• Ubuntu
  • Ubuntu 16.04 LTS (Xenial Xerus)
  • Linux kernel version 3.13.0-34-generic or later is required.
• CentOS (support is experimental)
  • Centos 7, fully updated.
  • Linux kernel version 3.10.0 or later.
• openSUSE (support is experimental)
  • Leap 42.X, fully updated.
  • Linux kernel version 4.4.X or later.
• Secure Shell (SSH) client and server that support public key authentication
• Network Time Protocol (NTP) client for time synchronization (such as ntpd or chronyd)
• Python 2.7.x
• en_US.UTF-8 as the locale

CPU recommendations

• Compute hosts should have multicore processors with hardware-assisted virtualization extensions. These extensions provide a significant performance boost and improve security in virtualized environments.
• Infrastructure (control plane) hosts should have multicore processors for best performance. Some services, such as MySQL, benefit from additional CPU cores and other technologies, such as Hyper-threading.

Disk recommendations

Different hosts have different disk space requirements based on the services running on each host:

Deployment hosts

A minimum of 10 GB of disk space is sufficient for holding the OpenStack-Ansible repository content and additional required software.

Compute hosts

Disk space requirements depend on the total number of instances running on each host and the amount of disk space allocated to each instance.

• Compute hosts must have a minimum of 1 TB of disk space available.
• Consider disks that provide higher I/O throughput with lower latency, such as SSD drives in a RAID array.

Storage hosts

Hosts running the Block Storage (cinder) service often consume the most disk space in OpenStack environments.

• Storage hosts must have a minimum of 1 TB of disk space.
• As with Compute hosts, choose disks that provide the highest I/O throughput with the lowest latency.

Infrastructure (control plane) hosts

The OpenStack control plane contains storage-intensive services, such as the Image service (glance), and MariaDB. These hosts must have a minimum of 100 GB of disk space.

Logging hosts

An OpenStack-Ansible deployment generates a significant amount of log information. Logs come from a variety of sources, including services running in containers, the containers themselves, and the physical hosts. Logging hosts need sufficient disk space to hold live and rotated (historical) log files. In addition, the storage performance must be able to keep pace with the log traffic coming from various hosts and containers within the OpenStack environment. Reserve a minimum of 50 GB of disk space for storing logs on the logging hosts.

Hosts that provide Block Storage volumes must have Logical Volume Manager (LVM) support. Ensure that hosts have a cinder-volume volume group that OpenStack-Ansible can configure for use with Block Storage.

Each infrastructure (control plane) host runs services inside LXC containers. The container file systems are deployed by default on the root file system of each control plane host. You have the option to deploy those container file systems into logical volumes by creating a volume group called lxc. OpenStack-Ansible creates a 5 GB logical volume for the file system of each container running on the host.

Network recommendations

Note

You can deploy an OpenStack environment with only one physical network interface. This works for small environments, but it can cause problems when your environment grows.

For the best performance, reliability, and scalability in a production environment, consider a network configuration that contains the following features:

• Bonded network interfaces, which increase performance, reliability, or both (depending on the bonding architecture)
• VLAN offloading, which increases performance by adding and removing VLAN tags in hardware, rather than in the server's main CPU
• Gigabit or 10 Gigabit Ethernet, which supports higher network speeds and can also improve storage performance when using the Block Storage service
• Jumbo frames, which increase network performance by allowing more data to be sent in each packet