Consider configuration management

According to a report released by Gartner in March, entitled 'When Servers Go Virtual: The Impact on Configuration Management', the virtual server environment boasts dynamics that don't feature in the physical world.

Says Gartner: "Many IT organisations approach configuration management in their server infrastructure in a piecemeal fashion. With the advent of virtual server technology, new complexities can undo even modest past configuration management progress.

"IT organisations should begin to act with a new urgency to not only ensure they have a comprehensive plan to address physical server configuration management needs, but to also incorporate virtualisation's new configuration-related dynamics as part of their overall configuration management blueprint."

The report says that although there are many benefits to the use of virtualisation technology (such as deployment agility and reduced capital costs), there are challenges such as dealing with the potential for greater mobility and the speed of change. Virtual servers are not only increasingly opaque, but they may also become more transient.

Configuration management tools lack the ability to support the virtualisation layer.

Gartner

Gartner adds that as opposed to the procurement of physical servers, the creation of virtual servers can be performed in a matter of minutes, with a limited ability to track changes throughout its lifecycle.

"Many configuration management tools lack the ability to support the virtualisation layer as well as the virtual guest," the report notes. Gartner's researchers have found that:

* IT organisation operations process maturity will be a key determinant to the development of an effective configuration management programme and the recognition that requirements for virtual servers must be included.

* Discovery is a cornerstone configuration management function, which will require new technical approaches as a consequence of the move to more fluid virtual server architecture.

* Patching will take on a new dynamic with virtualisation, thus requiring additional techniques to ensure systems are secured in their online and offline states.

* Configuration auditing will require new means to develop the requisite insight into virtual machines to track configuration drift and to ensure consistency is identifiable and remediated.

With the above in mind, the analyst house recommends the following:

* If you don't have adequate configuration management controls over your physical server assets, then develop them now in tandem with provisioning your virtual servers. Ideally, the development of configuration processes and controls should occur before significant product implementations of physical or virtual environments.

* When implementing virtual servers, develop the same governance and controls for these new assets that you have for your physical environment, making note of where modifications need to be made.

* Purchase configuration management tools that can directly address the nuances introduced by a virtual server infrastructure.

"Although many functions for managing the configuration management lifecycle of a server can be adapted to support virtual servers (hypervisor-based hosts and virtual guests) via the use of established management agent technology, there is a new dynamic of virtualisation that is not accounted for by configuration management tools today: snapshots. "

Snapshots can be an effective means to restore a former version of a virtual machine, Gartner notes. "They can often be performed against a virtual machine in a variety of states (powered on, powered off or suspended). Snapshots of virtual servers not only take a picture of a virtual machine's disk status, but its memory and configuration state. However, snapshots can become a configuration management issue as well. This can affect patching, auditing and even future deployments of guests that were built from these snapshots."

Gartner makes the following recommendations:

* Snapshots need to be discoverable and have the same protections as other software artefacts applied to them.

* IT organisations should develop processes to not only test snapshots for their validity, but implement methods to tag them with their currency levels - manually if necessary.

* Source: Gartner - When Servers Go Virtual: The Impact on Configuration Management. Ronni J Colville, Cameron Haight, 31 March 2008.