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Microsoft technologies for virtualization

ASI Polo Scientifico-Didattico di Forlì

Windows 2008

On May 29th in the Mazzini room of the ASI Scientific Pole of the University of Forlì, Microsoft with their most famous speakers (e.g. Piergiorgio Malusardi) presented a seminar on its 360° virtualization solutions.
The seminar lasted a whole day from 10.00 to 17.00, the audience heterogeneous but not very large, mostly university students of Computer Science.
Initially and dutifully they talked a lot about the new Windows 2008 operating system which in my personal opinion is a very interesting platform, very flexible and very reliable in terms of security, stability and lightness.
Here is a brief list of some features of Windows 2008 that particularly interested and excited me:
· HA (High Availability) proven by 99.999%, here are already included all patches and updates, i.e. no more restarts for updates, no more system hangs (blue screen).
· Possibility to install the system in CORE version, i.e. only the necessary services and no GUI (graphical user interface) to reduce unnecessary RAM waste.
· IIS7’s highly flexible and automatable web load balancing. Already in the IIS6 version, the separation of web processes into worker processors allowed a scalability and reliability base that was easy to implement thanks to the good old NLB (Network Load Balancing), now through the possibility of reading the configuration of the web server in a shared disk and thanks to the integration with the Operation Manager (an element of the System Center that I will talk about later), IIS is no longer alone in having to manage web traffic, in case of need (automatically detected by Op.Manag.) this is able to raise a new web server which, reading the same configurations as the previous one, is positioned in load balancing of the first (for example it can raise a new Win2008 server as an instance of a virtual server image, or bring up in PXE Preboot Execution Environment a physical server that reads the desired image on a disk in the SAN, but maybe I’m getting confused with other competing technologies and partners – Citrix – J).
· Another curious feature is the possibility of inserting HotPlug CPUs, i.e. inserting hot processors, while the machine is on. Mhhhh interesting, too bad that hardware vendors don’t care about providing compatible devices. This could be very useful if the system did not hang in the event of a CPU failure, but could simply warn of the failure to hot-download its services to other redundancy machines and shut down gently.
· Innovative licensing system. In the case of Virtual Machines, it is possible to manage the operating system licenses elastically, as I can reuse the licenses of virtual machines that I have turned off without having to move and change the activation codes by hand.

Hyper-V and System Center Virtual Machine Manager

Now let’s come to the heart of the seminar, virtualization and how it is seen and implemented by Microsoft.
Hyper-V is the term coined by Microsoft to define its hypervisor, which I remember for the ignorant on the subject is the kernel useful for managing hardware resources (CPU, RAM, Network, Disk) and dividing them by managing them, separating them, isolating them from the various higher virtualized operating systems. What’s new compared to VMware’s well-known ESX and XenSource’s XenServer (oops – Citrix – ).
Well compared to VMware there is some difference, but compared to Xen absolutely nothing, it is rumored that Microsoft’s hypervisor is in the image and likeness of Xen (there is a deep and interesting partnership between Microsoft and Citrix).
Both hypervisors (the latter two) are microkernels, i.e. they are much smaller in size and in function than VMware’s hypervisor. The size is 800KB while VMware’s is 32MB, this is because VMware’s ESX contains the hardware drivers that will be presented to guest operating systems.
In the case of Microsoft and Xen there is a paravirtualization (enlightment in Microsoft’s coinage) the hardware drivers are not virtualized, this if on the one hand decreases the size of the Hypervisor layer, therefore the attackability they say, on the other hand makes the hardware less compatible with the various operating systems.
For the rest, I must dutifully emphasize that comparisons are always made with the less up-to-date versions of competitors. Comparisons have been made with version 3.0 of VMware’s ESX server, unfortunately for Microsoft VMware is not still waiting to be joined by competitors, but continues towards its path of leadership in the sector, version 3.5 has been released for several months now, while only today Hyper-V is in release candidate.
The interesting things are the speed with which Hyper-V is installed and the simplified management by the tools that are certainly much more consolidated than Microsoft (WMI – PowerShell – System Center).
Let’s come to some numbers on virtualization:
The market today sees 93% of servers not yet virtualized, 7% is divided into 4.9% in the hands of VMware and the rest is shared by the other competitors.
Estimates speak of 17% virtualized in 2010.
In Microsoft there is currently a strong internal virtualization, 2500 VirtualMachines per hour with a consolidation ratio of 16/1.
The two most popular Microsoft sites (technet.microsoft.com and msdn.microsoft.com) that receive 1000000 Hits/day and 2000000 hits/day run on virtual servers and enjoy the balancing logic I mentioned above; on occasion the IIS 7.0 VMs are automatically installed when needed and when they are no longer needed they are deactivated. This is useful in periods of heavy load when patches or new versions of software are released, for example.

System Center

The very interesting platform is certainly the system center which is the management software that centralizes all the physical and virtual infrastructure, administers it in everything, and can be expanded with more and more components, it is a very versatile software as under each administration plugIn there is a series of code lines of code function in powerShell, this new very powerful and easily programmable administration shell born from Microsoft.
PowerShell uses WMI (Windows Management Instrumentation – an old and widely used platform of low-level scripting administrative functions by Microsoft) and is also used by VMware for the remote administration of the virtual infrastructure.
Here I can safely say that Microsoft far exceeds the VirtualCenter management software of the VMware Infrastructure, suffice it to say that the management limits of the VMware Virtual Center are 200 physical hosts in the new version, while the System Center is 400, where, however, the System Center is certainly a more scalable platform.
In addition, the System Center can manage VMware Hypervisors with the Virtual Machine Manager and in the next release also Xen Hypervisors with which it can even exchange Virtual Machines, as they comply with the same standard. Here Microsoft claims that the high HA reliability of the various clusters will be managed transparently by the System Center, in the sense that each cluster of the same hypervisors will manage its own HA and in the future perhaps it will be possible to do HA between Hyper-V and Xen.
On explosive features such as VMware’s V-Motion, Microsoft can only say “very nice but for now we don’t implement it yet, we are busy releasing our first release”.
The Microsoft cluster limit is 16 hosts, like the Xen Server limit, while currently VMware has a limit of 32 hosts. These limits are not very important for the logic of virtualization which is consolidation, management and provisioning speed and energy and management savings, but in a future perspective, still quite remote, where the hardware will only have to be an expansion to be added when resources run out and the system will have to automatically configure the new hardware to add resources, then they will make the difference and here those who will adopt or develop the filesystem capable of hosting infinite simultaneous accesses will dominate. At present there is only the google filesystem, the IBM global filesystem and the very recent Lustre filesystem or ZFS by SUN.

SoftGrid

I leave out the news of terminal services and virtual desktops, because they do not hide anything striking at least for me, emphasizing the Application Virtualization which is a big conceptual novelty.
First of all, let’s say that softgrid is a technology that Microsoft acquired by buying the company that had “invented” it.
We say first what it does and then how it does it.
Think you have a normal PC with a normal operating system (windows). Now let’s take the example of wanting to use the office 2000 suite and at the same time the office 2007 suite, we all know that it is not possible to install them at the same time, how should we do it?
We could configure Virtual Machines with two different Office installations.
Or use a remote office package that streamed from the server can make me use word2000 and word2007 at the same time as if they were installed on the machine and even see in the task manager of my operating system two separate word processes and even find no trace in the registry of any office package, that is, not having any installation on the office machine.
Also, I turn off my desktop in the office where I have just written two documents in word2000 and word2007, go home, turn on the laptop, connect to the office network and open the same two word 2000 and 2007 and find the exact same work configurations and the same documents if they are resident on the server as they should.
Well I’m also saving office licenses, because I don’t have to do as many installations and also I don’t have to buy as many licenses as there are employees in my company or how many desktops I have installed, because they could not work at the same time for a matter of time zone or if I’m out for business I don’t need the office package. If they are then with customers and cannot connect to the network to open the word and write the order, since there is a streaming logic behind it, the stream may have been downloaded locally and work unsynchronized and then synchronize once reconnected to the company LAN.
Now what does streaming of an application stream mean, well it’s not easy, but if we try not to think of a streaming movie and think that instead of the compressed bits of a video codec we are receiving compressed and encrypted bits of the files essential to the functioning of an application, we have all understood that they are the same thing, think that behind SoftGrid there are the normal streaming web servers and as such they can also be balanced. Another nice thing that I would call a technological virtuosity, but behind it there is a sociological reflection, it is possible to use my application even before the download is finished, precisely streaming, as when they want to see the preview of a video that we are downloading with emule, this is because if I click on an application and I don’t see anything until the upload is finished, I common human being recycle a thousand times creating only a thousand streaming streams of the same application.
Together with all the game that I have now listed, there is then the configurator of these packages, a software to create packages that can then be saved in a space managed by Active Directory and make sure that only the users I want have or not the right to use certain packages or even when the PC is turned on show them the packages they have to use and nothing else and not have installed any package on that PC, therefore if the PC dies, I don’t have to send the technician to repair the PC but only make the unfortunate user sit on another workstation.
It’s here to end a bit of the future at Microsoft :
I create an application to distribute, I create a template virtual machine that is useful for the purpose of the application, I close everything in a package and throw it into the group of servers managed by the System Center, therefore everything in a single box, this is called the Oslo Model, but only today the hyper-v is in release candidate, so be careful and wait a few more months before seeing our investments fail.