Contributed By: Cliff Hobbs [MVP SMS]
To me, VMware is one of the best pieces of software ever devised.  Why?  Well it allows you to run several ‘virtual machines’ (VMs) on one physical machine.  For example, in running FAQShop it would be really nice to have one machine running every piece of software we feature on the site.  So we’d have one box running MOM, another running SMS, another running SUS, etc.  But then add on the backend infrastructure needed to support this lot such as Domain Controllers, WINS servers, etc. and pretty soon you’re looking at a room full of kit.

This is where VMware comes in.  I can have one physical machine running say Windows 2000.  Onto this I install VMware.  Once VMware is installed I can then install several virtual machines running Windows, Linux or even Novell NetWare if need be.

How Does it Work?
You install VMware like any other piece of software.  You run Setup.exe and away it goes.  Once installed VMware allows you to create virtual machines.  VMware maps all of the physical machines resources such as CPU and memory to each virtual machine you setup.  So in effect each virtual machine has it’s own hardware resources.  Also, because the VMs are run as separate processes, if one falls over (this hasn’t happened to me yet, fingers crossed), it doesn’t bring others or in fact the whole machine down.

Once you’ve run through the wizard to create a virtual machine it’s just like having a new machine.  For example, if you want to build a Windows 2000 machine you select Windows 2000 from the wizard.  You then insert your Windows 2000 CD into the physical machine’s CD drive and power on the VM.  The VM ‘sees’ the Windows 2000 CD and boots off of it so you can start installing Windows 2000 onto your virtual machine.  Once the VM is created you can easily copy it between machines (the VM is stored in a single file), or make a copy of it so you can fire up and play with the copy and then if something goes wrong blow it away and re-copy the original again without having to start the build process from the beginning.

Uses for VMware
It goes without saying that before you undertake any sort of deployment using systems management tools or make any changes to the configuration of these tools you should run everything through your test lab.  But what if for whatever reason you don’t have a test lab?

Well this is where VMware can help.  All you need is a PC capable of running VMware and away you go.  For example you could have a domain controller running in one virtual machine with an SMS Site Server installed in a separate machine but still running on the same physical box.

Another example is that you could have your SUS server running in one virtual machine and then several SUS clients installed on separate virtual machines again all running on the same physical box.

You could even have two physical machines each running different VMs performing different tasks yet have the whole lot networked together so to the VMs they’re all running on the same physical network.

There are several other uses I can think of for VMware including:

• Studying – If you need to learn a new piece of software either as part of your job or to study for a certification exam one of the best ways of learning I find is by doing.  But the last thing you want to do is go playing with a live server, screw it up and then face the wrath of the boss.  Far better to install the software in a VM.  If you then get something wrong or you change something that has dire consequences then no harm is done as you can blow away the VM without having to rebuild the whole box.  If you want to build another VM just run the wizard and away you go.
   

• Software development/ testing/ support – If you’re writing code and not quite sure what that code is going to do to your machine then testing it against a VM is a no risk operation.  If the code screws up the machine you don’t have to rebuild your machine from scratch.
  
  The other good thing about VMware is that because you can run multiple OSs (one in each VM), you can test your machine against a machine running Windows 2000, another running XP, another running Windows NT, etc. without having to rebuild the physical machine ach time.
  
  From a support perspective you can have several VMs ready to roll so when a customer/ user phones up who is running a different OS or even a configuration specific to them there’s no rebuilding/ reconfiguring your machine – simply fire up the relevant VM.
   

• Training – There are several training companies ‘out there’ using VMware to run courses.  For example if you’re on a course looking at something like SMS for which you need a server it’s just a case of loading a VM with Windows 2000 already installed and it’s ready to roll.  When the course moves on to look at something like Software Distribution that really needs at least one client machine as well as the server it’s just simply a case of loading a different VM instead of having to have another physical machine or being told ‘we can’t show you this but you get the idea’.  From a training company’s perspective, re-configuring the classroom after/ before the next course is a very time consuming process.  With VMware it’s simply a case of creating the VM’s once for each course and then when the course is finished simply copying the relevant VM to the machine gets it up and running ready for the next course.
   

• Demos – How many times have you gone to a client, laptop under arm only to be asked ‘it would be really nice to see your software in action’?  Well now you can.  Simply create one or more VMs with the relevant software loaded and you’re ready to roll.
   

• Latest and Greatest and Legacy – We’ve all been there.  The client wants to run the ‘latest and greatest’ but either their current kit isn’t up to the job or you come across several mission-critical legacy apps that require Dos or something else weird and wonderful to run.  In the past the options have been dual boot (which wastes loads of time when it comes to switching environments); providing two machines (with this you’ve got the costs of the hardware initially and then ongoing costs plus the inconvenience to the user in having to find space for two machines on their desk); or finally leaving island PCs in departments that are dedicated to running the legacy app.  Well with VMware you can overcome all of these problems.

New to Version 4.0
Why should you upgrade from a previous version?  Well VMware 4.0 offers some great new features some of which are:

• Snapshots – Wouldn’t it be nice to be able to build a machine, then load your configuration settings/ customisation and at this point take a snapshot of the machine?  Then make a change.  If the change doesn’t work then you can revert back to the snapshot.  Then make another snapshot before making another change.  Again if it fails revert to the snapshot, if it works then make another snapshot, etc.  You get the idea.  With Version 4.0 you can take a snapshot at any time which you can then revert back to.  This overcomes the problem where you build and configure a VM to certain point and use this as a template.  You them make numerous changes to the copy and at some point a change screws up the VM.  Rather than having to revert back to the template and re-applying all of the changes you made up to the point where the last one failed (assuming you can remember what changes were made and in what order), you can simply revert back to the last snapshot.
   

• Tabbing Between Machines – One of the pains with the older versions of VMWare is that each time you wanted to load a different VM you had to start another instance of the software which filled up the Task Bar.  Well in version 4.0 you now load the software once and then simply click on the VM you want to load when you want to load it.  Want to load another VM?  Simply select it from the list and away you go.  Switching between VMs is now simply a case of clicking the relevant VM tab rather than having to click on the relevant instance of the program as you used to have to previously.
   

• Windows 2003 and Red Hat Linux Support – With version 4.0 you can run VMs based on these OSs out of the box.

There are plenty of other new and improved features which I shan’t bore you with.

My parting shot from experience is that if you’re going to be running several VMs on one physical machine then make sure that machine has plenty of grunt in terms of disk space and CPU but above all memory.  The more memory you can throw at VMware the better – just bear in mind that you’re running several machines on one physical box, each having their own requirements in terms of memory, disk space, CPU, etc. and you won’t go far wrong.

So there you have it.  VMware – a must piece of software for almost everyone in IT.

Don’t take my word for it.  You can download and evaluate VMware FREE for 30 days at: