Virtualization

[dd1313]

Hi GUys

Does Virtualization create a layer before the OS loads so that you can have multiple OS's
or does it need a host OS

THanks
DD

 

[Bismuth]

In my experience with VirtualBox, you will still need a Host OS, as it (Vbox) essentialy runs as an app.

You can dual-boot with multiples OSs, then select which OS you want to load at boot-up, but that is not virtualization.

B

 

[PallBearer]

Virtualization is an application that runs within a host OS, to run multiple OS's either install them all on partitions disks or choose a host OS and run the other OS's on the Virtul portion of the host.

 

[Asha'man X]

There are 2 main types of virtualization, host based and hypervisor based. Basically, host based is like Virtualbox or VirtualPC, where the app runs on an existing OS. Hypervisor based means that the virtualization software runs directly on the hardware, and then is responsible for managing the different OS's. Examples include Xenserver, Microsoft Hyper-V, VMWare and so on.

 

[Yucca]

There are 2 main types of virtualization, host based and hypervisor based. Basically, host based is like Virtualbox or VirtualPC, where the app runs on an existing OS. Hypervisor based means that the virtualization software runs directly on the hardware, and then is responsible for managing the different OS's. Examples include Xenserver, Microsoft Hyper-V, VMWare and so on.

Err vbox cab run on the hardware too directly provided you have the correct chipset like those from intel (look for virtulization technology).

 

[rurapente]

Vbox is not a hypervisor? Or at least it wasnt when i looked last.

 

[Yucca]

Vbox is not a hypervisor? Or at least it wasnt when i looked last.

If i remember correctly it is but only with the correct hardware as any software is only as good as the hardware it runs on. I will confirm this wehn my new lappie comes in a week or two.

 

[Yucca]

I think it is important to be clear that any VM ware is NOT meant for running a alternative OS on to replace your existing OS. These softwares are aimed at developers who do cross platform development to save on time which amounts to money that would otherwise be spent on system restart to boot a different OS. There is NO substitute for running Linux for eg. in a partition next to Windows. The only other reason I can recommend VBox is to save the hassles of fixing windows MBR and because it does not limit the OS like a partition install to x amount of persistent memory by allowing for dynamic resizing of HD space. If you are worried about installing Linux as an example because of what it may do to your system, there are many distros that run live of USB, CD or other alternative means.

 

[Conradl]

As stated before, there are two types of Hypervisor: A type one runs on bare metal, such as Citrix XenServer, VMWare ESX or MS HyperV. Type two is hosted and requires an OS, such as VirtualBox, Vmware Workstation and Server, and MS VirtualPC. The VT technology on a processor enables a guest OS to work directly with the processor, simplifying the virtualisation process process and increasing performance. A windows OS running on Xen for example requires VT to start; where a linux guest has the paravirtualised drivers required to run on a non-VT processor.

 

[Conradl]

Why on earth would you say that? There is a lots of reasons to use virtualisation in a non-dev environment. Mac users have been using parallels for years; I run several Linux machines in VMs. Virtual Desktops are becoming more popular, and recently VMware did some tests with SQL, showing a <1% impact in performance; so performance loss in a VM is no longer an issue....

 

[Yucca]

Why on earth would you say that? There is a lots of reasons to use virtualisation in a non-dev environment. Mac users have been using parallels for years; I run several Linux machines in VMs. Virtual Desktops are becoming more popular, and recently VMware did some tests with SQL, showing a <1% impact in performance; so performance loss in a VM is no longer an issue....

For the simple reason that it is meant for exactly what I say it is = meant for developers who need to test cross platform applications with taking systen boot up time out for the equation or a great deal there of. Yes there are indeed many people who have been using vm ware for running guest OS on top of their OS of choice but it would be ill advised to suggest that users go this way instead of just partitioning theirr OS on their HD as to save hardware costs for better machines that users may start to waste money on just for the task of trying a different OS. I am not talking about performance here. The other added benefits of virtual box for eg. are DIRECTLY aimed at the developer especially these days with netbooks as a developer can now create a very low resource environment for testing the bare minimum that they expect to run their application in. For the end user who wishes to run Linux as an example (I use linux as an example because it is illegal to run mac as a v machine) then much time and resources are saved by running the OS directly off the HD where over time better performance may be experienced.

 

[Spazmatic]

For the simple reason that it is meant for exactly what I say it is = meant for developers who need to test cross platform applications with taking systen boot up time out for the equation or a great deal there of. Yes there are indeed many people who have been using vm ware for running guest OS on top of their OS of choice but it would be ill advised to suggest that users go this way instead of just partitioning theirr OS on their HD as to save hardware costs for better machines that users may start to waste money on just for the task of trying a different OS. I am not talking about performance here. The other added benefits of virtual box for eg. are DIRECTLY aimed at the developer especially these days with netbooks as a developer can now create a very low resource environment for testing the bare minimum that they expect to run their application in. For the end user who wishes to run Linux as an example (I use linux as an example because it is illegal to run mac as a v machine) then much time and resources are saved by running the OS directly off the HD where over time better performance may be experienced.

Yucca, I have to agree with Conrad on this one.

 

[Yucca]

Yucca, I have to agree with Conrad on this one.

Fair enough i am not arguing against the idea in full, just adding that the main purpose of these softwares is for developers and people not in the know are probably better off trying an OS initially through such software but installing it on a partition if they plan on actually using it regularly For the purpose that more can be done with 100% unbuffered resources. Take my fave development tool which happens to be linux's compiz effects that allow me to run multipile desktops with hot key acess and some other enhancements. Such tools start to slow down when you run them on the host AND the guest. I may then need to install Linux as the host as and run windows as a guest to save on resources but I suppose this does not affect 90% of users of virtualBox.

It is a great software around and i was just trying to add that the true powers are exploited in full for cross platform development. I develop in Java as an example and can set each guest to have a different VM and develop a different Swing L&F and test them very quickly in different environments. I also use low end specs on some virtual machines and then test applications I wish to have on very low resource netbooks in a very low resource environment.

 

[Spazmatic]

I always thought the main purpose of the software was for consolidating large amounts of physical servers onto far fewer more powerfull servers.

 

[Yucca]

You are by no means incorrect. There are MANY uses for virtualbox(which I punt dearly here because it's my fave vmware) but many of them do not concern the average computer user who is looking for an option of running multiple OS. There is no substitute for running the OS u love directly off your hard drive.

I list some reasons why virtualbox appeals to me :

I develop application to run on any platform and then get to test it on:
a)Highe resource guest
b)Low resource guest
c)without needing masses amount of HD space for each guest as the HD storage exands dynamically
d)Develop on my host and leave each guest running while I change a look and feel as an example but now only need run it on each guest to see how it look as apposed to restarting each guest and deploying the application 1 by 1 which takes time for reboot.

This example can get very fragmented when I start to discuss the different browsers in each guest and other sub technologies like java webstart and Internationalization and localization.

 

[dd1313]

Hi GUys..which Virtualisation software is free/open source

THanks
Dev

 

[realbigdreamer]

Returnil Virtual System, Soft. Visualization, Solution, Virtual Box.

 

[Conradl]

Free open source:

Type 1 - Bare metal - Citrix XenServer (Free/Open, complete, full featured,built on the open source Xen), VMWare ESXi (Free, not as many features as the Citrix offering). MS HyperV (Free (depends), crap, bloated and not fully featured (even R2)), real

Type 2 - Hosted - VirtualBox (Free, and very good), VMWare Server (Free, but not as good as VBox), MS Virtual PC (free, but really, really poor)/