[Openstack] [GLANCE] Proposal: Combine the "container_format" and "disk_format" fields in 2.0 Images API

Donal Lafferty donal.lafferty at citrix.com
Fri Dec 2 09:48:06 UTC 2011


During October I noticed that Microsoft's vhdtool.exe creates VHDs that XenServer can't understand.  Boy was that painful.  The underlying problem is that some vhd's should be described as VM specific.

Does this suggest we adopt MIME-like syntax for category specialization?  E.g. in the same way we see "video/x-ms-wmv" we might see " vhd/x-ms-tools".  In this case, its easy to parse out the "vhd" category.

 
 
> -----Original Message-----
> From: openstack-bounces+donal.lafferty=citrix.com at lists.launchpad.net
> [mailto:openstack-bounces+donal.lafferty=citrix.com at lists.launchpad.net] On
> Behalf Of Jay Pipes
> Sent: 01 December 2011 15:53
> To: openstack at lists.launchpad.net
> Subject: [Openstack] [GLANCE] Proposal: Combine the "container_format" and
> "disk_format" fields in 2.0 Images API
> 
> Hey all,
> 
> OK, so I'm almost done with Draft 3 of the OpenStack Images API 2.0 Proposal.
> While doing this, however, I have come to the conclusion that the
> container_format we added in the Cactus timeframe just makes things more
> confusing and should probably be removed.
> 
> We have two fields in the current API that store information about the disk file
> format and any container/package format for an image.
> 
> http://glance.openstack.org/formats.html
> 
> The disk_format field currently allows 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
>     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
> 
> For container formats, we currently allow:
> 
>     ovf - This is the OVF container format
>     bare - This indicates there is no container or metadata envelope for the
> image
>     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 problem I see is that really OVF is the only real "container format" and I'm
> just not sure it's useful to have users set a container format. The goal was to
> allow Glance to report that the image file stored in Glance is an OVA file and
> not an image file itself. An OVA file is a single file that contains the OVF
> directory structure tar'd up. However, I think this can be more easily
> accomplished by consolidating the disk and container formats in the
> 2.0 API to just a single format field with the possible values:
> 
>     ova - This indicates the data stored in Glance is an OVF container that may
> actually contain multiple virtual appliances that has been tar'd into the single-
> file OVA format
>     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
>     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
> 
> What do people think of this proposal to combine the two into a single "format"
> field?
> 
> Thanks in advance for your feedback,
> -jay
> 
> _______________________________________________
> Mailing list: https://launchpad.net/~openstack
> Post to     : openstack at lists.launchpad.net
> Unsubscribe : https://launchpad.net/~openstack
> More help   : https://help.launchpad.net/ListHelp




More information about the Openstack mailing list