Is there a private cloud software that hosts a virtual machine on different physical servers?

Question

Cloud computing

Descriptions of cloud providers (for example, habrahabr.ru/company/cloud4y/blog/128243/ ) and reviews (for example, linuxdays.ru/clouds/33-smart-cloudorg/35--qq?start=3 ) hint that you cannot order a virtual machine in the cloud (or, more generally, a set of resources on which a specific OS can be installed, for example, Windows 2008 Server) with a dynamic increase in resources to values ​​exceeding the resources of the most powerful physical server in the cloud.

That is, simply put, there is no technology yet that would allow running a virtual machine in the cloud, some of the processes of which would work on one physical server, and some on another.

Is it really true? Close enough from the solutions for creating my own clouds, I only know Joyent Smart Data Center, such a thing will not work in it (at least in the versions I know - because they are based on the Illumos core and virtual machines on KVM / QEMU). What about the rest? Does anyone know what Amazon EC2 is made on inside? Oversun? Scalaxy?

A separate question about the dynamic increase in resources: am I right in believing that no server OS from Microsoft can detect new processors and memory dynamically added to its hardware configuration (read - to the corresponding virtual machine in the cloud)? Those. will you have to shut down the virtual machine, add memory and processors in the configuration and start the machine again?

Answer 1

Is it really true?

Yes

A separate question about the dynamic increase in resources: am I right in believing that no server OS from Microsoft can detect new processors and memory dynamically added to its hardware configuration (read - to the corresponding virtual machine in the cloud)?

For Windows Server Enterprise Edition, you can add memory without shutting down the server; for Datacenter, you can add memory and processors.

Answer 2

Existing solutions are very slow and, fortunately, they were buried in the 2.6.24 kernel area.
Compare the latency of a modern system bus, and even if it is optics, you will understand that now this is impossible while maintaining an adequate speed of processors and memory.

Answer 3

Amazon EC2 is built on Xen by Citrix.
They do not hesitate to admit that they use open source and do not give back their developments, they explain this by the fact that they do not sell the product itself on Xen, they sell services, and it doesn’t matter what services are already made on. True, they gave some Xen bug fixing back to Citrix, so the company is still a “good company”.

Answer 4

Google for the word NUMA. It has nothing to do with virtualization, Linux itself can “spread” over several servers. However, at the same time, you need to understand that there will be no magic, and the latency between the individual nodes of a single server will be STRONGLY greater than with local execution.
In other words, NUMA can be used, but not as a "transparent" technology, you need to think about it.

Answer 5

openstack.org/

Answer 6

I don't really understand why? set up a cluster, “smeared” across physical machines, balancing by ip, dns, etc. well, ESXi can give away more resources than there are physical ones, as far as I understood from 4.1, but why, if it hits performance

Answer 7

high availability for virtual machines is not it?