Controlling boot behavior with a config drive

A config drive is a read-only, unpartitioned, 64-MB block device that is attached to a server during build. The device is formatted to comply with ISO 9960. By default this drive contains server-specific metadata such as networking at launch. User-specified files can be added to this drive for the purpose of injecting data into the server.

The config drive’s contents are accessible only when the drive is mounted. If the operating system supports accessing disk by label, the config drive is labeled config-2.

The config drive is used primarily as a data source for cloud-init. If cloud-init or cloudbase-init is present, the config drive is automatically mounted.