In a review of Parallels Desktop, InfoWorld Test Center Chief Technologist, Tom Yager, affirmed:
…But it is accepted that client software virtualization is too slow and resource-hungry to be of practical use to professionals. As a result, client virtualization has gone virtually nowhere.
The sentence is there to back the idea performances can go back to normal with paravirtualization.
This couldn’t be more far from truth.
Performances on desktop machines strictly depends on available resources. In the same way it happens on server machines.
VMware Workstation and Server (formerly GSX Server) share same engine and virtualization performances are equal given same available resources and same operating system situation (amount of started services, memory manager settings, swap file, etc.).
It’s not a secret if you try to run a virtual machine on a typical laptop with 256 Mb RAM and an old Centrino processor your system will hang, inable to provide enough memory and processor power for all requests.
It’s not a secret if you try to run a virtual machine on a typical laptop with a default installation of Microsoft Windows XP SP2 you’ll have worst performances of a Windows Server 2003 SP1 with hardening and memory optimization for background services.
Virtual machines requires, in physical desktops, laptops or servers, enough resources. Not having them will translate in slow performances, in all scenarios.
In no cases this depends on virtualization.
It’s true paravirtualization significantly increase performances over traditional virtualization (sometimes called hardware virtualization, others called server virtualization), but it still needs enough resources.
Another 2 important points:
- a professional in need of virtualization doesn’t run a typical laptop with 256 Mb RAM and an old Centrino processor. If he does, he didn’t understand how virtualization works.
- client virtualization has gone everywhere.
In my experience, at today, there is no high level professional, in every field except graphic (due to actual technology limitations), which has not adopted virtualization on his desktop.
Software developerd, system or network engineers, security professionals, sales agents, marketing manager, accounting staff, conference speaker, classroom teachers. Everybody. Literally.