Xen for office use and network boot - virtualization

I'm trying to understand if Xen can fit my needs:
I need to have a Windows 7 image that I can copy to different machines (with different hardware) to have kind of default installation for every new entry in the office and faster replacement.
Is that possible to use the hypervisor for this?
Is that possible to use network boot as well of the hypervisor not to install Xen on every machine?
Edit: Will I be able tu use multiple displays?
Thanks.

It is possible if and only if you have installed Xen on every machine on your network that is not a good idea. Xen and other type-1 hypervisors are usually used to multiplex a high-end server into a set of virtual machines. Xen is also known for its para-virtualization technique which is not applicable for Windows.
Have you ever thought of VDI (Virtual Desktop Infrastructure) solutions? It enables you to have all your operating systems on a single machine and transfer the desktop to the clients.

Related

hypervisor and what does it do?

I understand servers are set up to run virtual machines with user applications in cloud settings and will have a hypervisor instead of a host operating system, I was curious why is the hypervisor use in place of the host operating system?
The hypervisor is used to do the abstraction between the physical and the virtual resources. In other words, it is responsible to create a virtualized layer and share the hardware components (CPU, RAM, NIC, storage) to the virtual machines that will be used. Therefore, it is a lot simpler to centralize and manage multiple sources of heterogeneous elements. It is possible to deploy two types of hypervisors:
Type 1 Hypervisor:
There is no actual operating system installed on the bare metal server except the software used to deploy the hypervisor. It is especially used in an enterprise context considering that you maximize the resources to share (you do not have the limitation of running an underlying operating system), but it also possible to deploy one in a home lab if you have the required hardware. A classic example is a VMWare ESXi host.
Type 2 Hypervisor:
It consists of installing the hypervisor on top of the actual operating system (Windows, Linux, MacOS). It is used especially for testing, deploying simple services and to extend your software capabilities (you can run multiple different operating systems simultaneously). A classic example is Oracle’s Virtual Box.

Why Xen requires an OS though it is a Type I Hypervisor?

Xen is a Type I hypervisor that means it can run directly on hardware so why do we need to install Ubuntu or CentOS or any OS to run Xen? It should run directly on the hardware as it's a Type I hypervisor.
The reason that an OS is needed is because Xen itself does not directly provide any mechanism for creating/managing virtual machines. Because these tasks require things like creating disk images, editing configuration files, setting up networking etc. It would be wasteful for the Xen project to reimplement all of this functionality when it is already included in widely-used OSes like Linux.
The only way to interact with Xen is by making hypercalls, some of which can only be made from the dom0 (Domain 0) VM. As noted in the Xen wiki this means that the hypervisor can be left to just the tasks which only it can perform - checking page tables, allocating resources for new domains, and scheduling domains.
I'm not aware of any type 1 hypervisor which does not need an OS in one way or another - many of them use Xen under the hood, with a custom OS. Things like VMWare ESXi (which does not use Xen) bundle their own OS as part of the distribution so still have an OS running on top of the hypervisor to provide needed functionality.

Newbie Hypervisor Questions

If I install a bare-metal hypervisor (say, ESXi), would it allow me to run Windows 7 concurrently with Linux?
Would it allow me to run multiple instances of Windows 7?
When I'm sitting at the PC that's running Win7 and Linux on a hypervisor, which OS do I see when I look at the screen? (I'm suspecting that the only way to access either OS is to do a remote login.)
Assuming the answer to #2 is yes, how do you manage multiple installs of Win7 on the same hard drive?
Thanks in advance!
If you simply want to run Linux and Windows in parallel you may of course do this on e.g. ESXi. Still, the OSes would run with virtualized (or emulated) hardware available to them, i.e. you would not be able to easily access all the hardware directly and the hypervisor itself not only introduces an overhead but this overhead is not deterministic.
If you want to run an RTOS (like Real-Time Linux) or any other RTOS, then you need a "real-time hypervisor".
You can google for such hypervisors - there are a few out there.
(I dont want to recommend one here as we are a vendor of such a solution our selves)
Regards
GFL

How do i create a VM Ware Image of an AIX LPAR?

I want to clone a AIX LPAR and was wondering if the physical machine could be converted into a VM Image?
I have used the VMWare Converter to create a VM Image of a physical windows box and the documentation states that you can do that for Linux Boxes too.
http://www.vmware.com/products/converter/
I don't see information on AIX or the other UNIXes.
If creating an VM Image of an existing physical AIX box is not feasible is there any easy way to clone the AIX image to another AIX machine.
The primary intent is to avoid re-creating the setup that is already performed for the current AIX box and we want a duplicate environment with the same setup.
VMware supports x86 (and x86_64) architectures for host and guest only. IBM AIX runs on the Power architecture, and VMWare does not do architecture emulation, so what you want does not exist.
If you want to back up/clone your AIX instance to another machine, look for information regarding mksysb and AIX Sysback.
You might want to take a look at the following, but there are no guarantees, and I'm fairly certain running AIX on anything but a Power architecture is still not a reality at this time:
Qemu
PearPC
Based on further reading, i understand that VMWare does not support AIX. The guest OS can primarily be Windows, various distros of LINUX and Mac-OSX. I also see Solaris as a supported guest OS, but i don't see AIX. So i don't think this is possible.
I would have to look at the Virtualization features supported from IBM for this activity.
Thanks,
Manglu

How can developers make use of Virtualization?

Where can virtualization techniques be applied by an application developer? How can virtualization be applied on a day-to-day basis?
I would like to understand from veteran developers making use of it. I am interested in the following things:
How it helps in development.
How it could be used for testing purposes.
What are the recommended practices.
The main benefit, in my view, is that in a single machine, you can test an application in:
Different OSs, in case your app is multiplatform
Different configurations, like testing a client in one machine and a server in the other, or trying different parameters
Diffferent performance characteristics, like with minimal CPU and RAM, and with multicore and high amounts of RAM
Additionally, you can provide VM images to distribute applications preconfigured, be it for testing or for running applications in virtualized environments, where it makes sense (for apps which do not demand much power)
Can't say I'm a veteran developer, but I've used virtualization extensively when environments need to be controlled. That goes for:
Development: not only is it really useful to have VMs about for different deployment environments (e.g. browser versions, Windows XP / Vista / 7) but especially for maintenance it's handy to have a VM with the right development tools configured for a particular job.
Testing: this is where VMs really shine: it's great to have different deployment environments that can be set back to a known good configuration and multiple server instances running in parallel to test load balancing.
I've also found it useful to have a standard test image available that I can run locally to verify that a fix works. If it doesn't then I can roll back to the previous snapshot with no problems.
I've been using Virtual PC running Windows XP to test products I'm developing. I have clients who still need XP support while my primary dev environment is Vista (haven't had time to jump to Win7 yet), so having a virtual setup for XP is a big time saver.
Before each client drop, I build and test on my Vista dev machine then fire up VPC with XP, drag the binaries to the XP guest OS (enabled by installing Virtual PC additions on the guest OS) and run my tests there. I use the Undo disk feature of Virtual PC so I can always start with a clean XP image. This process would have been really cumbersome without virtualization.
I can now dump my old PCs at the local PC Recycle with no regrets :)
Some sort of test environment: if you are debugging malware (either writing it or developing a pill against it) it is not clever to use the real OS. The only possible disadvantage is that the viruses can detect that they are being run in the virtualization. :( One of the possibilities to do it is because the VM engines can emulate a finite set of hardware.