[Openstack] Glance x-image-meta-type raw vs machine

Ewan Mellor Ewan.Mellor at eu.citrix.com
Mon Jan 17 08:43:37 UTC 2011


If by "appliance format" you mean "disk image + metadata about the VM" as distinguished from plain disk images, then the combination of a VMDK and a VMX could be considered to be an appliance format.  If you mean something richer (e.g. an "appliance" must be able to describe multiple VMs) then I don't think that it falls into that category.  It really depends upon what you're trying to do with this information (something that I don't understand, yet).

I don't care what we call it.  Whether it's "VMX" or "VMDK" or "VMX+VMDK" or "VMware", it's all going to end up meaning "proprietary goop" at the end of the day.

I agree with Diego (elsewhere in this thread) that VMDK subtypes would be useful metadata for Glance to be able to provide.  They may need to be streamed or unpacked differently as they move from Glance to a compute node, so if Glance has that metadata, then we don't need to do autodetection on the way through.

It would probably be best if you allowed arbitrary key-value pairs for metadata.  That way, we're free to figure out later which subtype info we need to collect. 

Cheers,
 
Ewan.

> -----Original Message-----
> From: Jay Pipes [mailto:jaypipes at gmail.com]
> Sent: 14 January 2011 18:02
> To: Diego Parrilla Santamaría
> Cc: Ewan Mellor; openstack at lists.launchpad.net; John Purrier
> Subject: Re: [Openstack] Glance x-image-meta-type raw vs machine
> 
> 2011/1/14 Diego Parrilla Santamaría
> <diego.parrilla.santamaria at gmail.com>:
> > Well... VMX is probably too VMware oriented. My only concern about
> this kind
> > of proprietary parameter file is you don't really have the chance to
> control
> > its lifecycle. New versions, changes... and developers lagging behind
> of
> > this changes. It can be a nightmare.
> > But this is more a decision of Product Management than a technical
> > decision... from my perspective. From a pure user perspective, the
> more
> > options the better, of course.
> > BTW, I think we did a good job in Abicloud about virtual disk formats
> and
> > virtual
> images: http://abiquo.org/display/ABI16/Virtual+Images+Introduction
> 
> Helpful link, thanks Diego :)
> 
> Followup question, based partly on the table of supported disk
> formats: instead of the general VMDK as a disk format, should we have
> a more broken-down format for, say, sparse VMDK?
> 
> In other words, how fine-grained should the metadata about an image in
> Glance be?
> 
> -jay


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