The May 2008 beta of System Center Virtual Machine Manager (VMM) 2008, combined with a second Hyper-V release candidate, shows that Microsoft is likely to release both products before the end of 2008. VMM aims to manage both an organization's library of virtual machines (VMs) and the physical servers hosting the VMs because management will ultimately be as important to successful server consolidation as actual virtualization features are. Although VMM can manage Microsoft and VMware virtualization products and has good features for day-to-day management of VMs, a key feature requires tight interaction with System Center Operations Manager.

Managing Large-Scale Virtualized Datacenters

VMM is a software tool for provisioning, managing, and storing VMs for hardware virtualization. Hardware virtualization enables multiple OS instances to run simultaneously on a single physical host computer. Each such "guest" OS instance runs in a VM that emulates a complete computer in software, including the processor, memory, graphics card, network interface, and storage devices (such as disk and CD-ROM drives). This emulation gives the guest what appears to be exclusive control of the hardware, but in reality the hardware is shared with other OS instances. Although hardware virtualization was initially used to test applications and application configurations, organizations are now using virtualization to consolidate production applications onto fewer, better utilized servers.

VMM can manage VMs that run on several different hardware virtualization products, including the following:

• Hypervisor products, such as Windows Server 2008 Hyper-V or VMware ESX, which are thin software layers that run directly on the server's hardware
• VM monitors, such as Microsoft Virtual Server or VMware Server, which are applications that run on a host OS.

Administrators can manage VMs from a VMM management console (which resembles the Operations Manager console), or through the PowerShell scripting environment. Console tasks are executed as PowerShell scripts that are displayed by the console, and administrators can save these scripts, then edit and reuse them as command-line scripts, which are easier to automate than console actions. PowerShell scripts can also be called by other scripts.

VMM relies on SQL Server (VMM includes the free SQL Server Express) to store VMM configurations; VM resources (such as hardware and OS profiles) that describe the environment in which VMs can run; and VM templates, which are used as models for deploying new VMs.

The VMM library stores and catalogs the many large files generated by virtualization products, including the following:

• VHD files for inactive VMs
• CD or DVD images (e.g., ISO files) used as alternatives to physical media for software distribution
• Hardware profiles, which are hardware specifications for a specific VM and contain information such as CPU type, amount of memory, and the priority given to the VM when it is running
• OS profiles, which provide the most common OS settings, such as the computer name and domain or workgroup settings.

Profiles and templates are created in the VMM administrator console either by wizards or from the PowerShell command line.

Authorized users can manage their own VMs with a VMM self-service Web application called the Delegated Provisioning User Interface. For example, developers could be allowed to create and deploy VMs for testing applications during the development process. The VMM administrator configures self-service policies to determine which users can use the self-service portal and which VMs they can create on specified physical host servers.