openstack-ansible/doc/source/install-guide/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 all hosts within an OpenStack-Ansible environment meet the following minimum requirements:

• Ubuntu 16.04 LTS (Xenial Xerus)/Ubuntu 14.04 LTS (Trusty Tahr)
  • OSA is tested regularly against the latest Ubuntu 16.04 LTS Xenial point releases and Ubuntu 14.04 Trusty as well.
  • Linux kernel version 3.13.0-34-generic or later.
  • For Trusty hosts, you must enable the trusty-backports or repositories in /etc/apt/sources.list or /etc/apt/sources.list.d/. For detailed instructions, see Ubuntu documentation <https://help.ubuntu.com/community/ UbuntuBackports#Enabling_Backports_Manually>.
• Secure Shell (SSH) client and server that supports public key authentication
• Network Time Protocol (NTP) client for time synchronization (such as ntpd or chronyd)
• Python 2.7.x must be on the hosts.
• en_US.UTF-8 as locale

CPU recommendations

• Compute hosts with multi-core processors that have hardware-assisted virtualization extensions available. These extensions provide a significant performance boost and improve security in virtualized environments.
• Infrastructure hosts with multi-core processors for best performance. Some services, such as MySQL, greatly 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

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

Compute hosts

Disk space requirements vary depending on the total number of instances running on each host and the amount of disk space allocated to each instance. Compute hosts need to have at least 100GB of disk space available. Consider disks that provide higher 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. As with compute hosts, choose disks that provide the highest I/O throughput with the lowest latency for storage hosts. Storage hosts need to have 1TB of disk space at a minimum.

Infrastructure hosts

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

Logging hosts

An OpenStack-Ansible deployment generates a significant amount of logging. 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 enough to keep pace with the log traffic coming from various hosts and containers within the OpenStack environment. Reserve a minimum of 50GB of disk space for storing logs on the logging hosts.

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

Each control plane host runs services inside LXC containers. The container filesystems are deployed by default onto the root filesystem of each control plane hosts. You have the option to deploy those container filesystems into logical volumes by creating a volume group called lxc. OpenStack-Ansible creates a 5GB logical volume for the filesystem 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, deployers should consider a network configuration that contains the following features:

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