The OpenStack Compute service is a cloud computing fabric controller, which is the main part of an IaaS system. You can use OpenStack Compute to host and manage cloud computing systems. This section describes the OpenStack Compute configuration options. To configure your Compute installation, you must define configuration options in these files: nova.conf. Contains most of the Compute configuration options. Resides in the /etc/nova directory. api-paste.ini. Defines Compute limits. Resides in the /etc/nova directory. Related Image service and Identity service management configuration files.

You can use nova.conf file to configure where Compute logs events, the level of logging, and log formats. To customize log formats for OpenStack Compute, use the configuration option settings documented in .

There are different methods of authentication for the OpenStack Compute project, including no authentication. The preferred system is the OpenStack Identity service, code-named Keystone. To customize authorization settings for Compute, use the configuration options documented in . To customize certificate authority settings for Compute, use the configuration options documented in . To customize Compute and the Identity service to use LDAP as a backend, refer to the configuration options documented in .

Resize (or Server resize) is the ability to change the flavor of a server, thus allowing it to upscale or downscale according to user needs. For this feature to work properly, you might need to configure some underlying virt layers.

Resize on KVM is implemented currently by transferring the images between compute nodes over ssh. For KVM you need hostnames to resolve properly and passwordless ssh access between your compute hosts. Direct access from one compute host to another is needed to copy the VM file across. Cloud end users can find out how to resize a server by reading the OpenStack End User Guide.

To get resize to work with XenServer (and XCP), you need to establish a root trust between all hypervisor nodes and provide an /image mount point to your hypervisors dom0.