"By allowing users to run Linux and Windows from a single workstation at the same time, VMware cuts hardware costs and streamlines development processes"
Disregarding issues of monopolistic practices, open-source debates, and vendor loyalty, most techies agree that the perfect computing model would include a single, standardized operating system that meets everybody's productivity and programming needs.Unfortunately, new and revised operating systems are developed and released on a regular basis, which brings us further and further away from a standardized OS, even though many of these releases reduce programming costs and marginalize interoperability issues.Developers and support teams, who must somehow account for a growing number of platforms while programming and troubleshooting, suffer the real headache behind this lack of OS standardization. And the associated hardware costs are no picnic for an enterprise's bottom line either.To cover all their Windows and Linux-variant bases and to save on hardware costs in the process, many development and technical support departments have begun turning to emulation utilities that allow users to run multiple OSes on the same workstation.VMware's recently released VMware 2.0 is an attractive example of such a solution. Running on Windows NT, Windows 2000, and Linux, VMware 2.0 provides multiple virtual computers on a single host, allowing you to mix and match applications and operating systems to your heart's delight without constantly rebooting. For this colossal convenience and for its top-notch usability, VMware 2.0 earned a score of Very Good in our testing. We tested the product under Windows NT 4.0, using it to run SuSE Linux 6.4 and Windows 2000 on virtual machines. In this scenario, Windows NT 4.0 was the host OS, and SuSE Linux and Windows 2000 were guest OSes.We first installed and configured two VMware 2.0 VMs (virtual machines) using a built-in configuration wizard and then layered our operating system choices on top.Our installations of SuSE Linux and Windows 2000 closely mirrored the processes we would have taken to install the OSs on a physical PC. For example, under Windows 2000, we were able to run Fdisk and format virtual disk partitions, detect virtual devices that were mapped to physical devices on our system, and make display adapter and networking choices. Overall, we spent about an hour installing each OS.VMware 2.0 supports a wider variety of peripherals and devices than do previous versions of the product. Nevertheless, it does not support the use of DVD, CD-R, or CD-RW drives. The software also runs exclusively on x86 platforms, which means computers with non-x86 architecture, such as Apple Power Macs or Sun Workstations, are left out in the cold.Modus OperandiEach VM requires an exclusive chunk of allocated memory and physical hard disk space. VMware recommends having a minimum of 128MB on your workstation to run a VM and active applications on both the host and guest OS. In our opinion, the more memory you throw at VMware, the merrier. Our test station was equipped with 512MB of RAM, and we allocated 128MB to each VM. Overall we were happy with the performances of both the Linux and the Windows 2000 VMs.VMware 2.0 works with two types of storage: your existing partitions (raw disks) and virtual disks. Virtual disks are more convenient because they allow you to add operating systems to your workstation without repartitioning your physical hard drive. The disks can therefore be easily backed up, restored, or even copied to another workstation. Another useful feature of virtual disk files is that disks created under VMware 2.0 for Windows can be used under VMware 2.0 for Linux and vice versa. Ultimately, this can help decrease your system administration costs and storage overhead.Regardless of your storage choice, disks in VMware 2.0 virtual machines operate in one of three modes: persistent, nonpersistent, and undoable. In the persistent mode, disks behave as do conventional disks, with permanent changes made to the image. The nonpersistent mode allows you to discard changes made to the VM at the end of each session. The undoable setting allows you to decide whether to keep or discard disk changes at the end of each session.We found the undoable mode to be the most appealing, as it allowed us to recover from self-induced errors, such as system crashes or registry problems, by discarding all changes and simply restarting the virtual machine.Isolation boothVMware 2.0 VMs are fairly isolated from each other and from the host OS. We deliberately crashed our Windows 2000 VM without it affecting the performance of our Windows NT host or the operation of SuSE Linux.But because it can also be convenient and desirable to have your VMs interoperate, VMware provides two primary forms of networking: bridged and host-only.Bridged networking uses a virtual ethernet adapter to allow a VM to appear as a full-fledged host on your network. This means that the VM can use any and all services available on your network, including printers, file servers, and gateways.Host-only networking is more restrictive. In this mode, VMs can only communicate with the host and other VMs on the same system. This is helpful for using workstations that may not be connected to a LAN or for isolating certain workstations from one another, often for security reasons.Round-upVMware 2.0, priced at $299, is too expensive for casual use across an organization. However, the software provides real utility to development and support teams that are required to work with multiple versions of operating systems. The ability to toggle among several VPNs on a single workstation will decrease your hardware costs and greatly boost your staff's productivity.
