What exactly is a private cloud?

Question

The term private cloud is rather confusing with all the definitions in different websites. Different people have different opinions on what is a private cloud.

1) As an aside, it should be noted that an increasing number of IT companies are also starting to use the term "private cloud" to refer to the building of a cloud computing infrastrucuture -- or "internal cloud" -- within a company's own data centre. Such a development is not really cloud computing at all, and may be regarded as a last-ditch attempt to maintain the status quo. Under any sensible definition, a "private cloud" has to be a cloud computing arrangement where the hardware concerned is owned and housed in a vendor's shared data centre" source:www.explainingcomputers.com/cloud.html

2) "Cloud" is simply a trendy term for "on someone else's computer". (That, by the way, is also a great handy way of deciding whether or not it's a good idea to move something to the cloud or not.) If you run processes on computers owned by someone else who has a data center specifically for providing this service, that's the cloud. Virtualization is not strictly necessary, but usually done because it's a better deal for the cloud provider.

A private cloud is the same except that your company also owns the data center (or maybe owns the company that owns the data center). Theoretically, if you're a customer of Amazon's cloud services, and one day you get really, really rich and buy Amazon wholesale, you've moved from cloud usage to private cloud usage without anything else changing.https://softwareengineering.stackexchange.com/questions/257952/who-provides-hardware-resources-in-private-cloud

Some of my lecture notes says that cloud computing does not exist without virtualization. But none of the above answers states that a private cloud has to use virtualization.There are also many different versions of answers for the same question. It is not easy to grab an understanding of such a term when different people interpret it in different ways.

Answer 1

My take on the subject of private clouds is to have one. More details can be found in my article Clouds of Trust. I have a private cloud that provides:

• Resilient networking via automated connect/reconnect of the boxes in the cloud
• Automated propagation of changes throughout the cloud ('git push' on one box leads to 'git pull' on other boxes)
• Publish/subscribe functionality for all the boxes in the cloud
• Secure exposure of all boxes in the cloud as servers, without the need to configure routers the boxes hide behind (via SSH remote port forwarding).

The cloud can be used to develop, test, and run a distributed application. It is a bash/javascript open source solution. You are welcome to join my cloud or build your own based off of my code.

Answer 2

Some of my lecture notes says that cloud computing does not exist without virtualization.

I personally think your lecture notes are incorrect on that point. You could do cloud computing without virtualization, provided that there was some way for the service provider to maintain control over the compute nodes sufficient to allow them to be remotely wiped and rebooted.

(And, yes it can be done easily. Many modern x86 / x86_64 systems have support for booting from a network. All you'd need extra is something to perform a hardware RESET remotely, and that is pretty easy to implement.)

However, as a general rule cloud computing is implemented using virtualization, both with public and private clouds. This is because virtualization allows you to get greater efficiency by share the physical hardware between virtual servers that are (typically) idle most of the time.

Finally, note that there isn't a single true definition of "cloud computing" or of "private cloud". The meanings of these terms are evolving ... just like the rest of the English language is evolving. Asking us which of the various opinions of what (for example) "private cloud" means is correct is ... asking for yet another opinion. There is no authority to decide whose opinion is correct. You just need to make up your own mind what makes most sense to you, and be prepared to change your mind.

If you are asking this in the context of revising for a test or exam, it is advisable to give maximum credence to your teacher or lecturer's opinion. That is just common sense!

Answer 3

Private cloud is a type of cloud computing that delivers similar advantages to public cloud, but through a proprietary architecture. Unlike public clouds, which deliver services to multiple organizations, a private cloud is dedicated to a single organization. so if you own a large business having its own changing needs, private cloud would be the answer for you. an example for private cloud vendor is stratoscale, i personally know them because my organization works with them.

Answer 4

Great answer at https://stackoverflow.com/a/12518827/46249 which quotes NIST's cloud computing definitions. Excerpted:

• Private cloud. The cloud infrastructure is provisioned for exclusive use by a single organization comprising multiple consumers (e.g., business units). It may be owned, managed, and operated by the organization, a third party, or some combination of them, and it may exist on or off premises.