Virtual Servers

Physical-to-Virtual
Conversions and New Installations

Miscellaneous

1

What factors have led to the emergence of Virtual Servers at this time?

2

Which Server Virtualisation program should I buy?

3

What are Snapshots and how do they differ from System Restore Points in Windows XP?

4

Should I store my company data on a virtual hard drive or a physical hard drive?

5

How do I insert a CD into an imaginary CD drive in order to install a program onto a virtual server?

6

Can a Virtual Server catch a virus?

7

Can you have Linux Virtual Servers and Linux Host Servers?

8

Is it safe to run other programs on the Virtual Server host computer?

9

Can I view, on-screen, the entire boot-up process of a Virtual Server?

10

Can I just make a copy of a virtual server's files on the host to get another virtual server?

11

What are Golden Images?

12

Can a Virtual Server created with one virtualisation program, be used in a different one?

13

Can a Virtual Server have a RAID array?

14

Why are virtual hard drives so small?

15

Does any preparatory work need to be done on a physical server before converting it to a virtual server?

16

Does anything need to be done after the conversion process?

17

How is Windows Product Activation (WPA) and other copy-protection schemes affected by the conversion process?

18

Can you convert a Virtual Server back to a Physical Server?

19

Why can't you guys spell "Virtualise" and "Virtualisation" correctly?

Q1

What factors have led to the emergence of Virtual Servers at this time?

A1

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Q2

Right now the virtualisation software industry is fast moving and unpredictable, so this answer may already be out of date.
The 2 main suppliers of virtualisation software for the Windows market are VMWare and Microsoft. Two more programs worth mentioning are:-
XenSource, an open-source virtualisation software project for Linux hosts only, and
Virtuoso from SWSoft which is for Windows and Linux hosts.
At present it's an easy choice of which one to pick for business-critical situations: VMWare.
Microsoft is playing catch-up in a situation that reminds me of where Netscape Navigator 4 and Internet Explorer 3 were in the mid 90's, and Microsoft went on to well and truly win that battle - Microsoft are promising much with their Viridian virtualisation technology due as part of Windows Server 2008.
Microsoft currently has 2 products: Virtual Server and Virtual PC.
VMWare has 4 products: VMWare Server, ESX Server, VMWorkstation and VMPlayer.
The following table summarises these 6 products:-

For most companies getting involved with virtual servers, the choice boils down to:-
"Do I have to buy ESX Server or can I get away with the free VMWare Server?"
VMWorkstation is also great to have for running test setups.
These are the things that ESX server can do that VMWare Server can't:-

Our advice is to start with VMWare Server and then graduate to ESX server if you need to.

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What are Snapshots and how do they differ from System Restore Points in Windows XP?

Snapshots are a feature of VMWare products which provide a means to restore a Virtual Server's hard drive to it's exact state at the time the snapshot was taken.
It's similar to taking a disk image of a physical server but the Snapshot file only stores the changes since the last snapshot so it doesn't require as much disk space as a full disk image.
The hard drive imaging program Acronis True Image Server has a similar feature where it can take incremental images of a physical server's hard drive.
Snapshots can be taken while the virtual server is running and it's a good idea to take a Snapshot prior to making any major change to the virtual server's configuration, such as before installing Windows patches or service packs.
It's interesting to compare VMWare's Snapshot feature with the System Restore function which is built-in to Windows XP:-

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Should I store my data on a virtual hard drive or a physical drive?

In a physical server you normally have 2 partitions, one for the operating system and program files and one for all your company data. This is because company data has different backup requirements to system files and so keeping the two separate helps.
Virtual servers are a fantastic way for keeping backups and providing disaster recovery for the system partition.
For data backups, conventional methods such as using a tape drive, off-site replication or a SAN are more efficient.
Unless you only have a small amount of data it's better to store your data on a physical drive on the host. It's usually more convenient to map a folder on the host's hard drive as a network drive on the virtual server. The host can then be responsible for backing up this data.
One of the big advantages of virtual servers is portability - if the current host fails they can quickly be moved to an alternative host - and so you don't want them to become disconnected from their data which may defeat their usefulness.
In some circumstances, keeping the data that a virtual server needs access to in a separate partition on the same virtual hard drive as the system partition makes sense as then the data is then "locked" to the virtual server.
Files stored on a real partition require roughly the same amount of storage space as when they are stored on a virtual partition. From the host computer's point of view, a virtual drive is just one large monolithic file and so when data files are stored on a virtual partition there's now an extra layer of abstraction compared with files stored on a real partition and you may not feel comfortable about this.
VMWare have a utility which allows a virtual drive to be mounted as a drive letter on the host computer, without any virtual servers needing to be operating, but it's not as straightforward to access files on a virtual hard drive as it is on a real hard drive.
If the host is trying to replicate a virtual server's data to another computer then large monolithic files are the enemy: a tiny change to one file on the virtual hard drive changes the 4gb file on the host and so requires the whole file to be re-replicated.

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How do I insert a CD into an imaginary CD drive in order to install a program onto a virtual server?

Although imaginary hardware is the big advantage of virtual servers, sometimes you need the real thing.
A real CD/DVD or Floppy drive, USB socket, printer or serial port on the host computer can be "attached" to the virtual server permanently or just for as long as you need it, with a few mouse clicks and without restarting the virtual server or the host.
Multiple virtual servers as well as the host machine can all access one physical CD drive at the same time.
If a program running on a virtual server requires a hardware dongle, one of the host's USB ports can be permanently assigned to it for the dongle.
If your host computer is at a remote site, such as a hosting facility, you can put a real CD into your local PC and use a program such as Magic ISO Maker to produce an "ISO" file which is an image of the real CD. Then transfer this ISO file to the host, over the Internet, so you can "insert" this virtual CD into the virtual server's imaginary CD drive - there's no need to use the host's physical drive for this. This is because VMWare server has the ability to mount an ISO file on the host as a CD drive on the guest.
Virtual floppies can be made and used in a similar way.
Virtual servers can be booted from real or virtual CDs and floppy disks to allow an operating system to be installed or repaired on the virtual server.
VMWare have proposed that a server's motherboard have a USB flash drive permanently attached to it containing a bootable image so a server will always have something it can boot from.

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Yes, and also become riddled with spyware.
A virtual server has the same vulnerabilities as a physical server.
It is therefore important to stick to the 3 rules of server protection:-

If a host is running several virtual servers it may be best to use a central software firewall/router on the host, such as Microsoft ISA Server 2006, so that individual virtual servers don't need their own firewalls.
Using the Snapshot function, you can quickly recover from a virus infection.

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The VMWare virtualisation products have strong support for Linux while Microsoft's products have no support.
Xensource only does Linux hosts.
You can buy a version of VMWare Server and Workstation for Linux hosts and ESX server has to run on it's own Linux host operating system.
You can run Linux guest PCs on the Windows versions of VMWare Server and Workstation.
The services offered by this website are for Windows Server guests running on Windows Server hosts and so we don't tend to mention Linux - no offence intended.
In a similar way we don't mention all the advantages of running Windows Workstation guests on Windows Workstation hosts even though we use them ourselves every day.
This is something people can usually manage to do themselves without outside help.

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Anything but the bare minimum of programs running on the host will be using up host CPU cycles and RAM which would otherwise be available to the Virtual Servers.
In smaller companies, servers have do to multiple jobs as IT budgets don't stretch to multiple physical servers.
Microsoft may recommend that Active Directory Domain controllers, Exchange servers and SQL servers are all installed on separate dedicated servers but they also sell Small Business Server 2003 Premium Edition where the Windows Domain Controller, Exchange, SQL and ISA server components must all be installed on the same physical machine.
There are few examples of combinations of server products that won't actually work. Having Exchange and Outlook installed on the same machine is often sited as a
no-no but I've seen these this combination used without any obvious problems.
The answer to this question is that it's a balancing act. If your physical server is capable of running 4 virtual server then, if you also get it to run another application, it may only be able to support 3 virtual servers.
If you only need 1 virtual server then it should run, quite happily, on top of SBS2003.
If you company requires half a dozen virtual servers, a dedicated host machine makes more sense.
If all your virtual servers on one host require some common services it can be more efficient to have the host provide these to all the virtual machines.
Installing an Internet firewall on the host, such as Microsoft ISA 2006 is better than installing it on all the individual virtual servers.
It may be better to have the host be in charge of backing up all the virtual servers' data files.

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I like to be able to sit in front of a real server and see all the BIOS and startup messages. Can you do that with a virtual server?

Yes. The virtual server window on the virtualisation program shows the whole boot process from Power On - you can even go into CMOS Setup and edit the BIOS settings if you want.
If you switch a virtual server instance to full-screen mode, the the monitor connected to the host will display the virtual server exactly as if it were a physical server and only a key-press combination (customisable) can break you out of full-screen mode.
A Ctrl+Alt+Delete is sent to the host and the virtual server so this is another way of breaking out of full-screen mode.

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Can I just make a copy of a virtual server's files on the host to get another virtual server?

Yes, it's is a good strategy to make regular backups of an important virtual server and store it on another server, maybe so that if the main host server fails, the virtual server can quickly be restarted on an alternative host.
On a Windows Server 2003 host the Volume Shadow Copy feature allows a running virtual server's files to be copied even though they are open.
It's important that such virtual server clones are not started simultaneously on the same network, as duplicate server names, IP addresses and Security Identifiers (SIDs) will cause mayhem.
You can also make a copy of a virtual server's files to create a clone that can then be used, as an additional server, on the same network as the original server. However, you should start the clone, for the first time, on an isolated LAN segment - virtual of course - and allow the VMWare program to assign it a unique virtual machine identifier.
Then download the SYSPREP utility from the Microsoft website and run it on the virtual machine. SYSPREP performs a mini-installation to generate new unique SIDs and allows you enter the appropriate licence key.
You must also give the cloned virtual server a unique Netbios name and IP address before allowing it to communicate with the same LAN as where the original server is running.

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What are Golden Images?

This is VMWare's name for a stock of virtual servers that have been prepared, ahead of time, to allow a new virtual server to be put into service quickly.
For example, you may have a Windows Server 2003 virtual server which is configured the way you like it,  is up-to-date with service packs and hotfixes and has antivirus installed plus other common utilities such as Sun Java runtime, Abode Reader and WinZip.
Starting with a copy of a Golden Image could save 3 boring hours of installing each new virtual server from scratch.
Golden Images are normally left turned off and perhaps fired up on an isolatd network and updated with patches once every few months.
Microsoft has now changed it's operating system licensing rules so that Golden Images don't require separate licences.
To turn a Golden Image into a production Virtual Server you would take a copy of the virtual server files, rename them, open them in, say, VMWare Server, run SYSPREP to create unique SIDs and enter the appropriate licence key, change the server Netbios name and IP address and install any extra programs and services required for the new server's role.

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Can a Virtual Server created with one virtualisation program, be used in a different one?

Yes, with a few proviso's.
VMWare has an option to import virtual machines created with Microsoft's Virtual PC or Virtual Server programs or a Symantec LiveState Recovery image however the one time I tried to import a Virtual PC machine, it didn't work.
Within the VMWare family of virtualisation programs, different programs are at different stages of development - usually VMWare Workstation has the more advanced features.
This means that a virtual machine created in VMWare Workstation may not work in ESX or VMWare server, probably due to differences in the virtual hardware components. It's a good idea, therefore, to create or convert a virtual server using the particular virtualisation program it is intended to be run on.
When a virtual server created on VMWare server is opened in VMWare Workstation you are offered the opportunity to upgrade the hardware - say "yes" only if you are intending to run the machine always in VMWare Workstation; it probably won't make any difference if you say "no, and stop asking".
It's not the end of the world if you have a virtual server running happily on VMWare Workstation and that you need to move to VMWare Server as the incompatible drivers can be removed manually.

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Our current server has a RAID hard disk array.
Can this be converted to a virtual server?

Yes, but in the conversion process the RAID array will be replaced with a single SCSI hard drive (an imaginary one).
As virtual hardware cannot fail, there's no point in having a "virtual RAID array" and the virtualisation software doesn't offer this as an option.
The type of virtual hard drive, IDE or SCSI, attached to a virtual server, has no bearing on the disk I/O performance a virtual server can achieve. This is determined by the speed of the host's hard drive system and the number of other programs running on the host plus any other virtual servers it has, all contending for hard drive access.
It certainly makes sense to have a fast RAID array installed on the host machine.

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Why is the capacity of a virtual server's hard drive so small in comparison to a physical hard drive. Is this a disadvantage of virtual servers?

It's actually a consequence of one of the advantages of a virtual server.
When you specify the hard drive capacity of a physical server you usually buy the biggest hard drive you can afford, one that you won't outgrow in 3 years because it's a big hassle if you have to upgrade a server's hard drive.
VMWare have a utility that can grow a virtual hard drive when necessary.
With a server's virtual hard drive you keep to the minimum you actually need right now and the default size for a Virtual Server's hard drive is therefore only 4gb.
This is enough to install Windows Server 2003 although if you plan to install something like Exchange on top of it you'll need at least 8gb.
Why 4gb? Well, it can fit onto a DVD.
The smaller you can keep the virtual hard drive the easier it is to manage backups etc.
If you want a 200gb virtual hard drive you can have one, as long as the host has this amount of spare capacity on it's real hard drive.

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Does any preparatory work need to be done on a physical server before converting it to a virtual server?

There's nothing you absolutely have to do but there are some things that will help:-

You can reduce the amount of disk space required for the System Partition to a minimum by:-
	Uninstalling programs no longer needed
	Moving any data from the System to the Data partition
	Deleting temporary files.
You should examine the Event Viewer logs and investigate and, where possible, fix any errors shown there.

 If you start the conversion process on a healthy machine you can be more confident that you'll end up with a viable virtual one.
If the reason you're converting the physical machine to a virtual one is because its hardware is about to fail then just get on with the conversion and leave any software problems for later.
In order for the conversion software to be initiated, the old server will have to come up from one more reboot.

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Does anything need to be done after the conversion process?

Here's what we recommend:-
Unless there are special circumstances not to, install VMWare Virtual Tools program (the Microsoft product has an equivalent) which make interacting with the virtual computer on the host a more pleasant experience.
Check the Event Viewer logs for any errors. There may be errors due to services that were installed to operate hardware now no longer present in the virtual computer. You should remove any such services.
Go to Device Manager and choose View - Show hidden devices
and then uninstall anything not present on the virtual machine.
Keep an eye on the Event Viewer logs and the log files of any other important programs running on the Virtual Computer over the next few days to be sure that everything is functioning normally in the virtual environment.
When you're confident everything's fine, make a backup of the virtual server's files and/or create a snapshot.
You can then take the original physical server out of service and dispose of it or put it to another use.
If the virtual server now has hard disk partitions way too big for what it needs or the size of these partitions aren't ideal, you can use a partitioning tool such as BootIt NG to change the partition sizes.

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How is Windows Product Activation (WPA) and other copy-protection schemes affected by the conversion process?

Copy-protection schemes, such as WPA, allow the programs they protect to keep operating only so long as none of the major hardware components of the computer they are running on, are changed - such as they would be if you simply made a copy of the program to another PC.
Even identical model PCs from the same supplier have unique codes hidden inside their components that the protection system can find.
A side effect of WPA is that if you change your network card or hard drive in your PC you may have to re-activate your copy of Windows which is, thankfully, a simple process.
Converting a physical server to a virtual server is like replacing every component in a computer with one of a different type. Needless to say that WPA notices this when you first start the converted virtual server. If you own a full Windows Server 2003 licence you have the right to move it to different hardware however if you have a server licence which the supplier of your server obtained from Microsoft at a significant discount you may not have this right.
So far, the only Microsoft server product that has hardware based copy-protection is Windows Server 2003.
Other suppliers of server-grade programs also use hardware based copy-protection but every one I've seen allows you to move it to a different server.
Re-activating software after a physical-to-virtual server conversion can be a pain and you should be sure that your licences are in order before beginning the process.

Larger companies purchase a Volume Licence Key (VLK) version of Windows Server 2003. These don't have WPA and all the servers use the same licence key. Using VLK versions of Windows server 2003 for virtual servers is certainly less hassle
The good news is that, once converted, the virtual hardware and its hidden codes remain constant and WPA doesn't know if it's running as a clone or backup copy of the server it was activated on.
WPA on a virtual server also doesn't care about the hardware in the host machine.

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Can you convert my virtual server back into a physical server if I decide I don't like it?

Yes, although so far as no one's ever asked me and so I haven't actually tried it.
You would have to make a disk image from the virtual hard drive, restore it to a real hard drive, connect this hard drive to a real server and replace the virtual hardware drivers with drivers for the new physical server's hardware.
This would be a manual process as, not surprisingly, VMWare haven't developed any tools to help with this conversion direction like they have done going the other way, with their P2V Assistant tool and P2V Boot CD.

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Why can't you guys spell "Virtualise" and "Virtualisation" correctly?

We're based in the UK where the above is the correct spelling.
We know that our American neighbours speak a different flavour of English but we're more reserved in our use of the letter Z (rhymes with "bed").

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