- Introduction
- The "Soft Lock"
- Creating a Virtual Development Environment
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Creating a Virtual Development Environment
For organizations willing to invest a little more in the support of their development platforms, another solution presents itself in addition to the soft lock: virtual development environments. According to Merriam-Webster's online dictionary, virtual reality is "an artificial environment which is experienced through sensory stimuli (as sights and sounds) provided by a computer and in which one's actions partially determine what happens in the environment."
This is exactly what happens. Virtual machine software creates one or more virtual PCs or servers on a real PC or server. Everything depends on what's available on the real machine: hard disk space, processor capability, and amount of RAM. These virtual machines can then support the installation and operation of any number of operating systems, including all versions of Windows, DOS, Linux, Novell, and so on. They can even communicate with the physical host just as if they were real machines in their own sense.
The possibilities are almost limitless. VMware Corporation, one of the manufacturers of virtual machine software, offers three different products for the creation of virtual machines: VMware Workstation, VMware GSX Server, and VMware ESX Server. Each supports different machine configurations for different purposes. The two server versions even support multiprocessing and allow the installation of multiple servers on a single physical machine. Imagine, if you will, a physical server operating under Windows 2000 and supporting virtual servers operating Linux, Novell, and even Windows .NET Server! This scenario is not at all impossible with VMware technology.
But for the support of development requirements, VMware Workstation is the ideal product (see Figure 4). Version 3.1 includes support for Windows XP and Windows .NET Server. It supports the creation of as many virtual machines as you have space on the hard disk drive. Each machine takes up about 4GB of space; not all of these machines need to run at the same time, though. Each requires a minimum of 128MB of RAM (256MB recommended). The base system also requires at least 256MB of RAM to support VMware. Each machine can host a different operating system. A developer operating with 1GB of RAM could actually have four machines running at once: the physical machine, and then three (maybe more) virtual machines. Switching from one to the other is as simple as switching from one window to another. No more reboots required!
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Figure 4 VMware supports the creation of several virtual machines. Click
the Power On button to start each system.
The virtual machine is in fact the ideal solution for local development support environments. The physical PC can always stay locked and stable according to IT requirements, and virtual machines can be used for testing and development. Developers can be local administrators of the virtual machines, while being simple users in the physical machine. And since every virtual machine can be treated as a physical machine within the network—a machine that can communicate with others either virtual or physical—IT can manage it the same way it manages all other machines (see Figure 5). In fact, IT can even send a command to the physical machine to wake up a virtual machine before initiating a software deployment—a sort of virtual "wake-on-LAN" feature.
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Figure 5 The virtual machine lets you operate another instance of an
operating system within your physical workstation.
Even better, since the virtual machine is only really a series of files within a special folder structure, it's a simple thing to copy and duplicate the operating systems that are installed inside them. This "disk image" capture of a virtual machine is very easy to perform. Several such images can be created when staging a virtual machine: Windows 2000 without service packs, with SP1, with SP2, with Active Directory, etc. It's even possible to apply Windows staging practices to these "disk images," allowing the duplication of a given image with a new name, new configuration, and so on. Thus IT can create one single virtual machine and deploy it to a number of developers through the use of Windows' System Preparation Tool (SysPrep.EXE).
Virtual machines are also easy to back up and restore. Since it's only a matter of copying a set of files, the developer can make regular backups at critical phases of the development project. If anything goes wrong, it's easy to return to an older version of the machine: Simply delete the current one and activate the older one. Once it's powered on, the original machine is back online.
VMware software doesn't just support the development environment. It can be used for several different situations—PC simulation for deployment testing, server simulation for consolidation purposes, application migration, software demonstration, training, legacy application support, you name it. The possibilities are endless.
A single license of VMware is required per physical machine, but a specific license is required for each operating system you install, even if you consider it the same machine. In actual fact, a single license is required for each machine you operate at a given time. If your system supports the operation of the physical system plus two virtual machines at once, two additional licenses are required for the operating system.
For $299 per PC, VMware Workstation 3.1 offers an ideal solution for the support of Windows and other development environments. This product finally offers IT full mastery of the local development environment. Coupled with the soft lock, the use of virtual machines can ensure complete satisfaction for both IT and developers. The return on investment is also almost immediate through productivity gains for both developers and IT. Finally, each can concentrate on their own tasks without hampering the other.