System administrationΒΆ
- Manage Compute users
- Manage volumes
- Flavors
- Compute service node firewall requirements
- Injecting the administrator password
- Manage the cloud
- Logging
- Secure with rootwrap
- Configure live migrations
- Live-migrate instances
- Configure remote console access
- Configure Compute service groups
- Security hardening
- Recover from a failed compute node
- Advanced configuration
To effectively administer compute, you must understand how the different installed nodes interact with each other. Compute can be installed in many different ways using multiple servers, but generally multiple compute nodes control the virtual servers and a cloud controller node contains the remaining Compute services.
The Compute cloud works using a series of daemon processes named nova-*
that exist persistently on the host machine. These binaries can all run on the
same machine or be spread out on multiple boxes in a large deployment. The
responsibilities of services and drivers are:
Services
nova-api
- Receives XML requests and sends them to the rest of the system. A WSGI app
routes and authenticates requests. Supports the EC2 and OpenStack APIs. A
nova.conf
configuration file is created when Compute is installed. nova-cert
- Manages certificates.
nova-compute
- Manages virtual machines. Loads a Service object, and exposes the public methods on ComputeManager through a Remote Procedure Call (RPC).
nova-conductor
- Provides database-access support for compute nodes (thereby reducing security risks).
nova-consoleauth
- Manages console authentication.
nova-objectstore
- A simple file-based storage system for images that replicates most of the S3
API. It can be replaced with OpenStack Image service and either a simple
image manager or OpenStack Object Storage as the virtual machine image
storage facility. It must exist on the same node as
nova-compute
. nova-network
- Manages floating and fixed IPs, DHCP, bridging and VLANs. Loads a Service
object which exposes the public methods on one of the subclasses of
NetworkManager. Different networking strategies are available by changing the
network_manager
configuration option toFlatManager
,FlatDHCPManager
, orVLANManager
(defaults toVLANManager
if nothing is specified). nova-scheduler
- Dispatches requests for new virtual machines to the correct node.
nova-novncproxy
- Provides a VNC proxy for browsers, allowing VNC consoles to access virtual machines.
Note
Some services have drivers that change how the service implements its core
functionality. For example, the nova-compute
service supports drivers
that let you choose which hypervisor type it can use. nova-network
and
nova-scheduler
also have drivers.