Archive for the ‘Virtualization’ Category
This article explains how to create a CentOS 6 image with VNC access on KVM for uploading it to the image store on OpenStack Diablo. I have used KVM running on Ubuntu 11.10 64-bit server for creation of the image.
Nova-volume provides persistent block storage compatible with Amazon’s Elastic Block Store. The storage on the instances is non persistent in nature and hence any data that you generate and store on the file system on the first disk of the instance gets lost when the instance is terminated. You will need to use persistent volumes provided by nova-volume if you want any data generated during the life of the instance to persist after the instance is terminated.
Commands from euca2ools package can be used to manage these volumes.
Here are a few examples:
Nova Manage commands
OpenStack provides commands for administrative tasks such as user/role management, network management etc. In all the examples we will use username as “novadmin” and project name as “proj”. All the nova-manage commands will need to be run as “root”. Either run them as root or run them under sudo.
Every nova user has a role associated with him. This role can be assigned at the time of creation of the account using “nova-manage add user…” or by editing the profile later using the Openstack Dashboard by the project manager. The role can be either global or project specific in scope. All access in Openstack is governed by roles. Each role has a predefined set of operations permitted within the relevant scope(global or local)
Cloud computing is a computing model, where resources such as computing power, storage, network and software are abstracted and provided as services on the Internet in a remotely accessible fashion. Billing models for these services are generally similar to the ones adopted for public utilities. On-demand availability, ease of provisioning, dynamic and virtually infinite scalability are some of the key attributes of cloud computing.
An infrastructure setup using the cloud computing model is generally referred to as the “cloud”. The following are the broad categories of services available on the cloud:
- Infrastructure As A Service (IAAS)
- Platform As A Service (PAAS)
- Software As A Service (SAAS)
Amazon Web Services (AWS) is one of the major players providing IAAS. They have two popular services – Elastic Compute Cloud (EC2) and Simple Storage Service (S3). These services are available through web services.
An instance is a virtual machine provisioned by OpenStack on one of the nova-compute servers. When you launch an instance, a series of steps are triggered on various components of the OpenStack. During the life cycles of an instance, it moves through various stages as shown in the diagram below:
There are several pre-built images for OpenStack available from various sources. You can download such images and use them to get familiar with OpenStack. You can refer to http://docs.openstack.org/cactus/openstack-compute/admin/content/starting-images.html for details on using such images.
For any production deployment, you may like to have the ability to bundle custom images, with a custom set of applications or configuration. This chapter will guide you through the process of creating Linux images of Debian and Redhat based distributions from scratch. We have also covered an approach to bundling Windows images. Read the rest of this entry »