An analysis of OpenStack docking vmware

Preface

This article is an analysis of OpenStack docking VMware, so this article focuses on the following two points:

• First understand its overall structure, and figure out why to use such a framework;
• Then understand the various components in the architecture, the main functions provided by the component and the interaction between the various components

Overall Architecture

First, learn about the overall architecture of OpenStack in conjunction with VMware.

working principle and process:

How does a virtual machine start?

The front-end bc-op or Horizon sends an HTTP request to the rest Api,nova API to select the appropriate nova-compute through the RPC call (RABBITMQ) Request Scheduler, which ends The normal process with OpenStack is the same, for KVM, directly on the compute node from the virtual machine can be, because the focus of this article is VMware so the process is relatively simple to write, for the docking of VMware that will continue to look down.

There may be multiple Nova-scheduler nova-compute, and each compute corresponds to a cluster (Cluster) on the vcenter.

Nova-compute the underlying driver that need to be specified in the configuration file is the VMware Diriver, which interacts with the Vcenter APIs that manage the ESX host cluster through VMware driver, and Vcenter chooses the appropriate ESX host in the cluster. Use Vcenter DRS internally to start a virtual machine.

By using OpenStack to start a virtual machine, the VM will appear on vcenter and support VMware's advanced capabilities, as well as the Horizon or OP pages, and can be managed like other OpenStack virtual machines. However, some VMware restrictions may apply (such as SSH keys, etc.).

How does the image get?

Like the Libvirt driver, VMware driver also interacts with glance, and the dashed line copies the VMDK image from the backend to the datastore of the boot VM and caches it.

How does the cinder Cloud drive manage?

As with the principle of the virtual machine, the Cinder backend is designated as VMware, using VMware's dirver to create the volume, cinder volume This is actually a layer of encapsulation, and ultimately call the vcenter storage management functions.

Summarize:

1. For end-user op or Horizon, there is virtually no difference between a KVM virtual machine and a VMware virtual machine, because the underlying virtual machines are managed through OpenStack, and the frontend is called OpenStack APIs.

2.Openstack as a management platform, can only manage to the nova-compute layer, that is, to know in which cluster, for the ESX level below, OpenStack is not managed, are entrusted to the vcenter management. In other words, the changes in the virtual machine within the cluster will have no effect on openstack management.

noun explanation

Vcenter

Unified management of resources such as all hosts (ESX) and virtual machines in the data center.

ESXI (ESX) host

Similar to a KVM host, computers that run virtual machines using virtualization software ESX or ESXI, provide CPU and memory resources to virtual machines, and

Provides the ability to access storage resources and network connections, and ESX is chargeable.

VSphere

VMware VSphere is a virtualized product of VMware and a total solution.

Datastore

The shared data store, which holds files such as virtual machine files and image files, is mounted to all ESX hosts for use.

Other Components

Others are OpenStack components that are not the focus of this article will not repeat.

Reference from OpenStack official documentation:

Http://docs.openstack.org/kilo/config-reference/content/vmware.html

VMware-related issues encountered:

1. During the test process, the glance upload image is slow and timed out.

Cause: The Vcenter version 5.1 version is too low to resolve the issue of upgrading vcenter version.

2. If the number of flavor CPUs created is not 2, the virtual machine kernel boot is not normal.

Cause: VMware's virtual machine defaults to the NUMA architecture (CPU accesses the respective memory), so there is a limit to the virtual CPU format.

You can esc into the virtual machine and turn off NUMA enabled.

3. When virtual machines are migrated through vcenter, OpenStack cannot manage virtual machines

Cause: As in the schema above, OpenStack manages to Nova-compute, as far as the operation under Vcenter is perceived, it is theoretically unaffected

An analysis of OpenStack docking vmware