Creating application images, using entire virtual machines or otherwise such as container-based, is a convenient way of “snapshotting” applications, allowing them to be able to seamlessly move such images from one infrastructure to another—including virtualized clouds. Today, there are a growing number of various image-based tools available that do, in fact, make it easy to “convert” from one virtualization format to another, offering the efficient portability of images across different infrastructures - including clouds. Regrettably however, most are quickly finding that moving an image is only part of the challenge in enabling an application on a cloud environment. Getting these images to actually work optimally, connect with each other and other resources while maintaining portability once on the target environment/cloud…is a real problem and one that is not addressed by this class of solution.
WHY IMAGES ARE CONSIDERED USEFUL – THEY SEEM TO HELP BYPASS COMPLICATED APPLICATION DISCOVERY
Due to the complicated nature of real-world enterprise applications and their deployments on existing IT environments, it is often considered difficult to discover such an application environment in its entirety for the purposes of cloud migration. While Image-based tools try to make this easier, they take an overly simple approach of “discovering” such existing IT environments. This is especially true for use cases that run legacy workloads, those that may have gone through a series of changes, upgrades and maintenance over their lifetime and, even those that have evolved through a series of changes of IT personnel. It is because of these real-world complexities that discovering such environments along with their custom settings such as dependencies on networking and storage infrastructure and operating environments can be an extremely tedious exercise to “get it right”. It is in fact this challenge that has created the allure of many image-based solutions as a part, or in some cases a replacement for, discovery
The sad truth however, is that even though these solutions have a place, IMAGES ARE NOT SUFFICIENT as, or as a replacement for, discovery. True discovery is needed in order to adequately orchestrate the provisioning, operations and management of applications on clouds and required for enterprise-class cloud computing.