openstack/deb-glance
Code Issues Proposed changes
9de8fc1eae
deb-glance/doc/source/formats.rst
Stuart McLaren fc0b47beb6 Add 'vhdx' disk format. 
This patch adds the Hyper-V 'vhdx' disk format to the Glance
configuration. This allows users to upload 'vhdx' images by default.

'vhdx' disks can have much larger storage capacity than the older 'vhd'
format [1].  (Plus, anything with 'x' in the name is awesome.)

DocImpact: Docs will need to be updated to indicate that the 'vhdx'
disk_format is now one of the default disk formats supported by Glance.

UpgradeImpact: Adds 'vhdx' to the default list of disk_formats.  Operators
will no longer need to configure specifically to use 'vhdx' disks.

[1] https://technet.microsoft.com/en-us/library/hh831446(v=ws.11).aspx

Spec-Lite: https://review.openstack.org/#/c/347626
Change-Id: I4e172c78d7afeb8be5a0123238efe3d8e4b044c9
2016-07-28 16:34:00 +00:00

3.2 KiB
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Disk and Container Formats

When adding an image to Glance, you must specify what the virtual machine image's disk format and container format are. Disk and container formats are configurable on a per-deployment basis. This document intends to establish a global convention for what specific values of disk_format and container_format mean.

Disk Format

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

  • vhd

    This is the VHD disk format, a common disk format used by virtual machine monitors from VMWare, Xen, Microsoft, VirtualBox, and others

  • vhdx

    This is the VHDX disk format, an enhanced version of the vhd format which supports larger disk sizes among other features.

  • 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

Container Format

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

  • ova

    This indicates what is stored in Glance is an OVA tar archive file

  • docker

    This indicates what is stored in Glance is a Docker tar archive of the container filesystem