At TechEd, held June 7 to 10 in New Orleans, Microsoft unveiled the technical details and timing of the first service packs expected for the Windows Server 2008 R2 and Windows 7 operating systems, which could be of particular importance to companies investigating the use of VDI, or virtual desktop infrastructure.
During his keynote, Bob Muglia, president of Microsoft's Server and Tools Business, announced the timing-the first beta will be delivered by the end of July-while the technical details were expounded in a series of breakout sessions over the course of the conference.
As has often been the case in the last several years, the service packs for the latest versions of Microsoft's client and server are contained in the same download package (for 64-bit, at least, as there are no 32-bit 2008 R2 editions). But while Service Pack 1 for Windows 7 won't contain much in the way of new features, instead rolling up those patches and fixes already delivered via Windows Update along with an updated Remote Desktop client, SP1 for Windows Server 2008 R2 will have a couple of significant enhancements.
The two most important new features for Windows Server 2008 R2, Dynamic Memory and RemoteFX, focus on enhancing both the back-end performance and end-user experience of virtualization workloads. Those running Remote Desktop Services servers or Microsoft's VDI services could immediately benefit from those features (particularly the former), while those running 2008 R2 for other roles will only get rolled-up hotfixes and some incremental improvements.
Dynamic Memory is a Hyper-V enhancement allowing the administrator to set a memory range on a virtual machine to improve VM density, allowing customers to squeeze the maximum performance out of host memory without paging to disk. Administrators define the low and high thresholds of memory for a VM, and the host and VM work together to assign memory to clients dynamically as needed for the client workload. So a VM with a base of 1GB of memory may only need that amount for basic operation, but will request more from the host when it starts a memory-intensive operation (opening a big Excel spreadsheet, perhaps.) Although the host pool of memory is shared between VMs, Microsoft claims it is done in a secure manner that does not provide the chance to perform memory reads across VMs.
Administrators can also configure a memory buffer on a per-VM basis, configuring Hyper-V to hold back a percentage of memory and not let it be used in other instances. Administrators can also set memory priority per VM, giving an order of precedence for those occasions when the virtual clients' needs exceed available system resources.
Although Dynamic Memory could have benefits for virtual instances of either Windows client or server, Microsoft representatives expressed the belief that virtual client instances-which have a greater variance in memory needs over time and workload-will likely be the biggest beneficiary of the feature. Servers, in their estimation, typically have more predictable memory needs.
Guest machines must be enlightened to support Dynamic Memory, however. At the start, the feature will only be available for Windows Server 2003 and 2008 (Standard, Enterprise and Datacenter editions in either 32-bit or 64-bit), and Windows Server 2008 R2 (64-bit, all editions). Also supported are the Enterprise and Ultimate SKUs of Windows Vista and Windows 7 clients (32-bit and 64-bit), but not the Business/Professional editions.