Microsoft Corp.s first virtual machine solution provides a solid set of virtualization capabilities and easy-to-use management features, as eWEEK Labs exclusive tests of Virtual Server 2005 Release Candidate 1 showed. Our tests of RC1 showed that Virtual Server 2005, which is slated to ship this fall, will be a handy alternative to the usual migration of legacy applications to a new hardware and software platform. Using Virtual Server, IT managers can rapidly roll out older applications to virtual machines running on a faster system.In addition, because Virtual Server can run older guest operating systems (NT and Windows 2000), IT managers can continue to support legacy applications on virtual machines while taking advantage of new hardware.Virtual Server 2005, which is based on technologies acquired from Connectix Corp. last year, will be available in two versions. We tested the Standard Edition, which can support four-way servers; the Enterprise Edition can scale up to 32-way servers and can support 64GB of memory. Microsoft has not yet disclosed pricing information for the final versions. Virtual Server 2005 can support almost any x86 virtual machines (as guest operating systems), but it must be installed on host servers running Windows Server 2003. By contrast, VMware Inc.s GSX Server can be installed on a wide variety of Linux host machines and also supports Windows 2000 hosts. Click here to read eWEEK Labs review of GSX Server 3. Before we installed Virtual Server 2005, we had to configure the test Windows Server 2003 host system as an application server, install IIS (Internet Information Services) 6.0 and enable ASP.Net extensions. Once that was done, it was easy to install Virtual Server 2005 and launch the Virtual Server Administration Web site using our Web browser. The Master Status page provides an overview of all configured virtual machines and can display the desktops of virtual machines that are running. Clicking on a virtual machine image opened a window that allowed us to access that particular virtual machine. Virtual Server creates VHDs (Virtual Hard Disks) to assign storage for the virtual machines and offers several disk formats. The VHDs can be configured as bootable partitions, fixed disks, dynamic disks, and differencing or undo disks. Dynamic VHDs allow the virtual machine storage disk to expand as data is added, and Virtual Server can warn administrators if a disk image grows too big on the host system. The differencing and undo VHD formats are very useful in software testing and development environments, offering administrators a great deal of flexibility when creating virtual machines. Differencing disks enable cloning of a parent disk configuration by propagating data changes onto each child disk, which allows administrators to quickly create a large set of similarly configured test clients. The undo VHD format does not write data on the disks during a virtual machine session but instead saves changes on separate files. At the end of the session, users can opt to keep or discard the changes. Virtual Server provides CPU resource allocation where users can allocate and limit host processor resources to virtual machines. Virtual Server can prioritize processor resources, and although it does not yet support virtual machine SMP (symmetric multiprocessing), the CPU allocation feature allows IT managers to have some control over virtual machine workloads. Microsoft plans to integrate Virtual Server 2005 with Microsoft Operations Manager 2005, Systems Management Server 2003 Service Pack 1 and Automated Deployment Services when these management solutions become available. Technical Analyst Francis Chu can be reached at email@example.com. Check out eWEEK.coms Windows Center at http://windows.eweek.com for Microsoft and Windows news, views and analysis.