When adding an image to the Image service (glance), you may specify what the virtual
machine image’s disk format and container format are.
This document explains exactly what these formats are.
The disk format of a virtual machine image is the format of the underlying disk image. Virtual appliance vendors have different formats for laying out the information contained in a virtual machine disk image.
You can set your image’s disk format to one of the following:
raw
This is an unstructured disk image format; if you have a file without an extension it is possibly a raw format
vhd
This is the VHD disk format, a common disk format used by virtual machine monitors from VMWare, Xen, Microsoft, VirtualBox, and others
vmdk
Another common disk format supported by many common virtual machine monitors
vdi
A disk format supported by VirtualBox virtual machine monitor and the QEMU emulator
iso
An archive format for the data contents of an optical disc (e.g. CDROM)
qcow2
A disk format supported by the QEMU emulator that can expand dynamically and supports Copy on Write
aki
This indicates what is stored in Glance is an Amazon kernel image
ari
This indicates what is stored in Glance is an Amazon ramdisk image
ami
This indicates what is stored in Glance is an Amazon machine image
The container format refers to whether the virtual machine image is in a file format that also contains metadata about the actual virtual machine.
Note that the container format string is not currently used by Glance or other OpenStack components, so it is safe to simply specify bare as the container format if you are unsure.
You can set your image’s container format to one of the following:
bare
This indicates there is no container or metadata envelope for the image
ovf
This is the OVF container format
aki
This indicates what is stored in Glance is an Amazon kernel image
ari
This indicates what is stored in Glance is an Amazon ramdisk image
ami
This indicates what is stored in Glance is an Amazon machine image
