62bbe0f38e
Disks requirements aren't clear, and people can think it's always required to have 1TB disk on cinder nodes. There is no hard requirement there, so we should remove this requirement, mark it as recommendation, and point its only for LVM backends. Change-Id: Ic45a7799e5092653d70fce9f2b6b7ae3f03d8775
4.8 KiB
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-genericor later is required.
- CentOS (support is experimental)
- Centos 7, fully updated.
- Linux kernel version
3.10.0or later.
- openSUSE (support is experimental)
- Leap 42.X, fully updated.
- Linux kernel version
4.4.Xor later.
- Secure Shell (SSH) client and server that support public key authentication
- Network Time Protocol (NTP) client for time synchronization (such as
ntpdorchronyd) - 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.
Storage/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.
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.
As with Compute hosts, choose disks that provide the highest I/O throughput with the lowest latency.
OpenStack-Ansible is able to deploy Cinder with a series of different
backends and uses Logical Volume Manager (LVM), by default. Hosts that
provide Block Storage volumes with LVM are recommended to have a large
disk space available allocated to a cinder-volume volume
group, which OpenStack-Ansible can configure for use with Block
Storage.
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.
Each infrastructure (control plane) host runs services inside machine 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.
Other technologies leveraging copy-on-write can be used to reduce the disk space requirements on machine containers.
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.
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