> I would agree that the simplest description of a public cloud is what
> you mention - "one that allows anyone to sign up(either freely or
> paid) to access the resources provided". Like amazon EC2, etc.
> The hybrid model mentioned is what I would describe as a private cloud
> that when needed can pull in or access resources of a public cloud.
> There do exists VCL provisioning modules in development that can
> request resources from EC2 and IBM's cloud. Xianqing Yu is working
> on a JIRA issue for interacting with an IBM cloud
> https://issues.apache.org/jira/browse/VCL-457 as an example.
I agree - but would like to add a non-technological dimension to the
We normally call the VCL a "private cloud" because that is how we and
most (all?) universities use it - and it could be a "hybrid cloud" if
the provisioning modules were running.
However, I think the real distinction is in how the VCL (or other
cloud) is *managed.*
The VCL can be run to allow anyone/everyone to log in access the
resources provided. This isn't done because of resource limitations,
license limitations, etc. - all real reasons but not technological
Therefore I'll even quibble with the above definition of a "hybrid
cloud" because the user interface is into a private cloud, and the user
ideally isn't even aware of where the cloud resources live and so just
sees it as a private cloud.
Bottom line: private/hybrid/public distinctions have both
technological and administrative meanings.