Technique used by Vmware ESX & XENServer

[microproc]

HI

What technique or technology used by vmware & XEN to virtualize the server. I know that the virutalized servers does not know about each other. What is para virtuailzation and where it is used in both (vmware & Xen)

[dmaster]

Hello microproc,

what is paravirtualization ? see this link :

With Xen en VMware Paravirtualization is used for linux guests only because a modification of the os is required and this will not work on windows oses.. i believe windows server 2008 is the first exeption..

with paravirtualization your os is aware that it is virtual.. if your os can use paravirtualization, it will have a performance increase because it uses now hardware virtualization

[dmaster]

Hello microproc,

one thing about Xen, when you want to run windows virtual machines you need a cpu with support hardware virtualization such as VT (Vanderpool Technology) on intel chipsets.

I think with Xen they managed to get windows oses running with paravirtualization but because the current windows oses can not realy benefit from you will not have a greater performance increase then they run on VMware main virtualization solution.

[RParker]

Funny thing about that... Microsoft Hyper V seems to be faster than VM Ware, at least in our test. So if paravirtualization is ultimately even faster, that would make Windows 2008 hosts even faster than Xen, VM Ware, or any of the bigger Virtualization products.

I am not recommending Windows 2008 by any means, because it's not just about speed, VM Ware gives you so much more in terms of capability and management. I wouldn't want to go the paravirtualization route for one reason, stability. ANY time you talk about modifying the OS, you have problems. Software depend on 100% compatibility across the board, if that doesn't work, the speed benefit you gain will be pointless.