neocoretech

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Application virtualization was the first available type of centralisation to offer increased resource optimisation with simplified operation.

However, a number of known problems remain, problems which are solved by migrating to workstation virtualization.

Certain applications originally designed to run on PCs fail to work when a system attempts to execute several instances on the same server. For instance: if an application directly calls a file for which the administrator is unable to customise the path, the first instance of the application will work, but subsequent instances will be unable to open a file that is already in use. The application will freeze because the instances run on a shared OS. With workstation virtualization, each application runs on a dedicated OS (on a dedicated virtual disk) just as with a conventional PC.

With a dedicated OS, when any one application monopolizes all CPU resources, all other applications suffer as a result. Similarly, if the shared OS freezes, all the instances will cease to function. With workstation virtualization, any overload and/or instability problems are restricted to the particular virtual PC. The hypervisor remains responsible for allocating CPU resources to ensure that the other virtual PCs continue to operate as normal.

Data can never be kept totally separate where several application instances run on a shared OS, because of the links that exist between them. With workstation virtualization, each virtual PC is totally independent from all the others, they do not share any data, they do not share any memory, etc.