A virtual machine image is a single file which contains a virtual disk that has a bootable operating system installed on it. Virtual machine images come in different formats, such as raw
and qcow2
.
An image store is where the virtual machine images managed by Glance reside on a persistent medium. While Glance currently has support for many different stores, the most commonly deployed stores are file
and swift
.
file
This store refers to a directory on a local file system where the glance-registry service is running. The directory could refer to:
- locally attached storage
- a remote, shared filesystem (e.g. NFS) - see the section called “Configuration of Glance with NetApp FAS”, or
- a remote block device that has been partitioned and a filesystem created within a partition - see the section called “Configuration of Glance with NetApp E-Series and EF-Series”
swift
- This store refers to an instance of the OpenStack Object Storage service (Swift).