One area that's particularly challenging and can quickly become a choke point on your journey to the cloud is the provisioning of both physical and virtual servers needed to deliver cloud-based services. Traditional methods, such as manual or script-based provisioning, are proving to be too costly and inefficient in this new era of IT services on demand. This problem only grows in scope and scale, the larger the enterprise, as users demand that massive workloads be frequently moved across many servers at a time, both in and back out of the cloud.
Script-based provisioning offers some advantages over provisioning servers by hand, one at a time, such as increased speed and a basic level of automation, but scripts still take time to write. They take even more time to maintain and update, due to the numerous changes that are frequently made to server configurations. Manual and scripted provisioning can be good solutions to use for the initial provisioning of a standard server image, or a-la-carte configurations, due to their flexibility and ability to customize. However, these methods simply cannot scale when hundreds, if not thousands, of servers and their workloads need to be brought online quickly, migrated, re-purposed or consolidated.
An Alternative Approach
Image-based provisioning is emerging as a viable alternative to scripted and manual provisioning methods capable of handling the demands of cloud computing for several reasons:
Speed: Image-based provisioning is dramatically faster than scripted provisioning. What used to take hours, if not days or weeks, can now be done in minutes.
Scalability: Standard system images can be multi-casted to multiple servers simultaneously, overcoming the bottleneck constraints of scripted or manual provisioning methods.
Portability: The most advanced image-based provisioning tools have the ability to move the entire personality of a system to either similar or dissimilar hardware, freeing your administrators from having to create and maintain separate images for each hardware vendor and server model in your environment.
Simplicity: Image-based provisioning can greatly simplify the server provisioning process. No scripts to build or maintain as routine, required steps in the provisioning process are automated to ensure a consistent build, each and every time.
An advanced image-based provisioning solution enables you to capture live system images from any physical or virtual server, and then provision them on-demand to any other physical or virtual server.
A server's complete system image (whether physical or virtual), including its applications, operating system, storage and network configurations, can be automatically captured and migrated to another physical or virtual server, even if the source and target servers are on different hardware platforms, operating systems or hypervisors. The technology compares the configurations of the source and destination servers and injects or reconfigures the necessary components and device drivers "in-flight" to ensure that the image can be run correctly on the new target server.