CPD 11 2018: Virtual desktop infrastructure

INTRODUCTION

There are many reasons why a growing number of companies are moving over to virtual workspaces, also known as the “digital workspace”.

Factors for consideration include the ease of managing the system, lower running costs, a better use of resources and streamlined operations and mobility. In recent years, many of the issues that previously held back an enterprise from moving to the digital workspace have been addressed as the technology has matured.

Thin clients – effectively centrally-managed computers that have no hard or disk drive – are now capable of handling elements such as advanced graphics, Voice over Internet Protocol and video streaming, making them much better adapted to running as an enterprise resource.

然而，在建筑、工程和建筑行业中，虚拟桌面技术的主要驱动力之一是建筑信息建模(BIM)模型的增长，主要尽管不完全通过使用Autodesk Revit。AutoCAD图纸过去使用许多较小的文件来创建分层的CAD项目模型。

WHAT IS REVIT?

Revit is a single application built for BIM with features for architectural design, MEP (mechanical, electrical and plumbing) and structural engineering and construction.

However, Revit is not BIM. Revit is built for BIM. Revit and other applications made for BIM help designers to design, simulate, visualise and collaborate in order to capitalise on the advantages of the interconnected data within a BIM model.

The key word in BIM is “information”. BIM is centred on models made up of objects. Revit creates these objects, which consist of data, which designers can see in different views – 2D drawings, 3D models and schedules, or lists. When one piece of data changes in one view, it is updated in all other views automatically by Revit because each view is displaying the same data.

对象也可以与其他对象相关。同样，如果一个对象发生了变化，任何相关的对象也会反映这些变化。

SHIFT TO BIM

The move to BIM allows different disciplines to work on their specific specialist areas independently. With BIM and Revit files, the numerous and unique disciplines are combined into a single multi-layered file.

However, just the sheer size of these creates problems for IT infrastructure, and when different companies need to collaborate on a project and share files, it can clearly be seen that BIM adoption has led to a variety of technical challenges.

幸运的是，虚拟桌面基础设施(VDI)的成熟正好赶上BIM Level 2的采用，因此为文件处理挑战提供了一个答案。

The general industry consensus is that CAD is moving from 2D to 3D, with 4D (time analysis), 5D (cost management) and finally 6D (facilities management) being not too far in the future. As BIM models grow in size due to the increase in content the technical challenges will continue to mount up on companies using traditional IT desktop infrastructures.

BIM collaboration is fast becoming a major driving force behind enterprise purchasing decisions, and a virtual workplace is well suited to accommodating this trend.

A virtual workflow is able to follow a user around, allowing tasks to be performed wherever they are located without losing the thread of what they were working on and without having to wait for a system to boot up. Users are then able to search the cloud for those files that they had open on their regular PC.

Coupled with an access control token or single sign-on (SSO) solution, a simple touch of the wrist or swipe of a card will almost instantly open the user’s profile, revealing what they were working on last time they tuned in.

ADDITIONAL BENEFITS

除了这些合作的好处，政府的2011年建设战略定义了BIM的四个级别，并在2016-2020年修订中规定，如果项目是中央资助的，任何从事政府项目的公司都有合同义务采用BIM级别2。

The long-term strategy for the UK is set out in the Construction 2025: industrial strategy document, published in 2013, and sets a forward-looking view of how the industry and government will collaborate in order to put the UK at the forefront of global construction.

Numerous references to “Digital Built Britain” within the various documents that make up the stages of BIM adoption state a target for “increasing maturity of BIM level 2 to a point that supports development of BIM level 3 at a later date” by 2020.

Reading between the lines, industry consensus is that the mandated adoption of BIM Level 3 is targeted for 2025. Level 3 BIM represents full collaboration between all disciplines by means of using a single, shared project model that is held in a centralised repository, allowing all parties to access and modify the same model, removing the final layer of risk for conflicting information.

This is commonly known as “Open BIM”. Current nervousness in the industry around issues such as copyright and liability are intended to be resolved – the former by means of robust appointment documents and software originator/read/write permissions, the latter by shared-risk procurement routes such as partnering.

The Construction Industry Council’s BIM Protocol makes provision for these. The adoption of BIM Level 3 is significant since it will implement a markedly different process of project participants updating a single, shared integrated building model in real time. As things stand today the only way to deliver this solution with the technical performance required to drive a multitude of very large files is VDI.

ENVIRONMENTAL CONSIDERATIONS

Virtual workplaces are also better for the environment, with market analysts at research firm Gartner estimating that the IT industry contributes a 2% share of total global CO₂emissions. Recent studies conducted by the Fraunhofer Institute for Environmental, Safety and Energy Technology in Germany revealed that a combination of IGEL thin clients and virtual desktops based on VMware View software (a commercial desktop-virtualisation product) proved to have 47% less environmental impact than a similar, PC-based environment.

Furthermore, a virtual desktop infrastructure created especially for BIM users is far cheaper to purchase and run than a high-end CAD modelling workstation environment, with thin clients costing substantially less than their “fat” counterparts, and running at as little as 1 watt of power when idle.

瘦客户机的耗电量平均比PC少61%到77%，相比之下，瘦客户机的成本平均比“胖”PC低30%到50%——这还没有考虑到虚拟环境的较低总成本。

ADDITIONAL DATA

Revit models support up to eight users working in the same BIM model – VDI provides the ability to deliver this access to subject matter, experts and various other types of CAD user located across different physical locations with ease.

Revit requires low network latency, so the workstation needs to be on the same Local Area Network (LAN) as the BIM data. VDI is the only answer to many of these issues, since if users are to collaborate from all parts of the world, they all need to be accessing Revit applications on the same LAN as the actual BIM data.

The recommended latency between VDI client and the Data Centre holding the Virtual Desktop and BIM data is a 180-200 milliseconds round trip.

A typical VDI client uses 300Kbps of bandwidth to deliver comparable high-end workstation performance and seamless adoption.

VDI的最佳实践是使用1:4的物理CPU和虚拟CPU，这意味着四个虚拟桌面可以共享一个物理CPU，这再次节省了成本。