On Mon, Feb 28, 2011 at 6:49 PM, Brian Lamar <brian.la...@rackspace.com> wrote: > Just because I can't help but asking, when does data specified during > instance creation stop being data and start being metadata? While it seems > like a silly question I'm wrestling with the idea of metadata actually > *doing* something.
I've brought this up as well. Metadata is data about the data's structure (or the data's container). Unfortunately, the CS API spec uses metadata to refer to free-form *properties* or *attributes* of the instance, and the decision was made to stick to what the API spec said to avoid confusion (didn't exactly work out that way, I know ;) ) > I was under the (perhaps false) impression that metadata could be added by > end-users and was a way to describe associated data about an object which > didn't impact it's being. For example, we don't set the image type with > metadata, instances are created by providing an image type. Perhaps the two > aren't analogous because if "openstack:near" changes the instance would > migrate to another location? Or if "volume-000001" was moved, does the > instance move too? The things that have so far been described as "metadata" are not metadata at all, nor are they "metacontent" (see below). They are merely attributes of the end-user request to allocate some resource. -jay for those of a like-minded curiosity about these things. From the wikipedia article on this same subject: "The term Metadata is an ambiguous term which is used for two fundamentally different concepts (Types). Although a trite expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at design time the application contains no data. In this case the correct description would be "data about the containers of data". Descriptive metadata on the other hand, is about individual instances of application data, the data content. In this case, a useful description (resulting in a disambiguating neologism) would be "data about data contents" or "content about content" thus Metacontent. Descriptive, Guide and the NISO concept of Administrative metadata are all subtypes of metacontent." _______________________________________________ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp
