In July, VMware announced the release of VMware Infrastructure 3 Suite, which provides a comprehensive set of data centre solutions based on a virtual architecture. Meanwhile, Microsoft announced that, by partnering with XenSource, it will support the running of Linux virtual machines under its Windows Longhorn Server product, due for release in 2007. IBM also announced a partnership with XenSource.
Virtualization is seen as one possible solution to managing the data center of the future; server virtualization enables the application view of computing resources to be separated from the underlying implemented infrastructure view. To achieve this, software is used to create a virtualization layer (also referred to as a hypervisor); this virtualization layer enables the host platform to execute multiple virtual machines (VMs). Each VM can run either its own copy of a different operating system, or multiple versions of the same operating system, but, importantly, it supports the pooling of resources (processor, disks, and memory) across a server based on policy rules defined by the organization.
However, two important limitations with the current technology are often overlooked. Firstly, server virtualization only pools resources within a physical server; it cannot currently pool resources between physical servers. VMware technology can manage multiple physical servers as one logical entity that can execute many VMs, and also supports the ability to move the VMs between physical servers.
Secondly, virtualization cannot virtualize the I/O of an X86 computer; it is currently restricted to memory, disk, and CPU. This is important, as if an organization’s performance bottleneck is their I/O, then virtualization alone will not help resolve the issue.
The impact of the Microsoft announcement is particularly interesting, as Microsoft appears to be trying to build another dominant position in the market, this time at the hypervisor level. Effectively, it wants the Microsoft hypervisor to be optimized for any Windows server, allowing other operating systems (such as Linux) to run on its hypervisor through translated calls, which would mean the Microsoft hypervisor retains control of the hardware on the server. However, this position is being challenged by VMware’s building of an API for the Linux kernel, and it hopes this will become a standard, therefore allowing the Linux kernel to run natively on any hypervisor.
In contrast, the IBM announcement is more benign. The company has been a partner with Xen for many years, and the announced support for XenSource on Intel- and Opteron-based processors and blades is increasing IBM’s ability to meet customer demands by having more open source products as part of its offerings.
These announcements appear to draw the battle-lines between the Microsoft-centric view of the world, and the open source community view of the world. With the predicted value of the virtualization market expected to reach $18 billion by 2007, you can be certain that this will not be the last we hear about this topic.
Source: OpinionWire by Butler Group (www.butlergroup.com)
