I continue to scratch my head not because of David's statements that he's yet to find any "killer applications" for Private Clouds but rather the continued unappetizing use of the definition (quoting Dimitry) of a Private Cloud:
In a nutshell, private clouds are Amazon-like cost-effective and scalable infrastructures but run by companies themselves within their firewalls.
This seems to be inline with Gartner's view of Private Clouds also:
The future of corporate IT is in private clouds, flexible computing networks modeled after public providers such as Google and Amazon yet built and managed internally for each business's users
My issue is again that of the referenced location and perimeter. It's like we've gone back to the 80's with our screened subnet architectural Maginot lines again! "This is inside, that is outside."
That makes absolutely zero sense given the ubiquity, mobility and transitivity of information and platforms today. I understand the impetus to return back to the mainframe in the sky, but c'mon...
For me, I'd take a much more logical and measured approach to this definition. I think there's a step missing in the definitions above and how Private Clouds really ought to be described and transitioned to.
I think that the definitions above are too narrow end exculpatory in definition when you consider that you are omitting solutions like
GoGrid's CloudCenter concepts -- extending your datacenter via VPN onto a cloud IaaS provider whose infrastructure is not yours, but offers you the parity in platform and support to your native datacenter.
In this scenario, the differentiator between the "public" and "private" is then simply a descriptor defining from whom and where the information and applications running on that cloud may be accessed:
From the "Internet" = Public Cloud. From the "Intranet" (via a VPN connection between the internal datacenter and the "outsourced" infrastructure) = Private Cloud.
Private clouds are about extending the enterprise to leverage infrastructure that makes use of cloud computing capabilities and is not (only) about internally locating the resources used to provide service. It's also not an all-or-nothing proposition.
It occurs to me that private clouds make a ton of sense as an enabler to enterprises who want to take advantage of cloud computing for any of the oft-cited reasons, but are loathe to (or unable to) surrender their infrastructure and applications without sufficient control.
Private clouds mean that an enterprise can decide how and how much of the infrastructure can/should be maintained as a non-cloud operational concern versus how much can benefit from the cloud.
Private clouds make a ton of sense; they provide the economic benefits of outsourced scaleable infrastructure that does not require capital outlay, the needed control over that infrastructure combined with the ability to replicate existing topologies and platforms and ultimately the portability of applications and workflow.
These capabilities may eliminate the re-write and/or re-engineering of applications like is often required when moving to typical IaaS (infrastructure as a Service) player such as Amazon.
From a security perspective -- which is very much my focus -- private clouds provide me with a way of articulating and expressing the value of cloud computing while still enabling me to manage risk to an acceptable level as chartered by my mandate.
I get all the benefits of elasticity, utility billing, storage, etc., don't have to purchase the hardware, and I decide based upon risk what I am willing to yield to that infrastructure.
David brought up the notion of proprietary vendor lock-in, but yet we see GoGrid has also open sourced their CloudCenter API OpenSpec...
Clearly I'm mad because I simply don't see why folks are painting Private Clouds into a corner only to say that we're years away from recognizing their utility when in fact we have the technology, business need and capability to deliver them today.
/Hoff