Assign FlexCast Models

Assign FlexCast Models

As with physical desktops, it is not possible to meet every user requirement with a single virtual desktop type. Different types of users need different types of desktops. Some users may require

simplicity and standardization, while others may require high levels of performance and personalization. Implementing a single desktop virtualization model across an entire organization will inevitably lead to user frustration and reduced productivity.

Citrix FlexCast offers a complete set of application and desktop virtualization technologies that have been combined into a single integrated solution. Because each FlexCast model has different advantages and disadvantages, it is important that the right model is chosen for each user group within the organization.

There are five FlexCast models available, the advantages and disadvantages of each model are described below:

• Hosted shared – With the hosted shared FlexCast model, multiple user desktops are hosted on a single server-based operating system and provisioned using Machine Creation Services or Provisioning Services. The hosted shared desktop model provides a low-cost, high-density solution, however applications must be compatible with a multi-user server based operating system. In addition, because multiple users are sharing a single operating system, users are restricted from

performing actions that negatively affect other users, for example installing applications, changing system settings and restarting the operating system. There is also the potential that a single user could consume an unfair share of resources, which may negatively affect other users. The hosted shared FlexCast model is provided by Citrix XenDesktop in combination with Microsoft Remote Desktop Services (RDS).

• Hosted VDI – The hosted VDI FlexCast model provides each user with a desktop operating system. Hosted VDI desktops are less scalable than hosted shared desktops because each user requires their own operating system. However, hosted VDI desktops remove the requirement that applications must be multi-user aware and support server based operating systems. In addition, the hosted VDI model provides administrators with a granular level of control over the number of virtual processors and memory assigned to each desktop. The hosted VDI model is provided by Citrix XenDesktop, and offers the following sub categories:

Random / Non-Persistent – Desktops are based on a single master image and provisioned using Machine Creation Services or Provisioning Services. Users are dynamically connected to one of the desktops in the pool each time they logon. Changes to the desktop image are lost upon reboot.

Static / Non-Persistent – Desktops are based on a single master image and provisioned using Machine Creation Services or Provisioning Services. Users are allocated a virtual desktop on first access. Once assigned, users will always be connected to the same virtual desktop. Changes to the

desktop image are lost upon reboot.

Static Persistent – Desktops are based on a single master image and provisioned using Machine Creation Services or Provisioning Services. Users are allocated a virtual desktop on first access. Once assigned, users will always be connected to the same virtual desktop. Changes to the desktop are

stored in a personal vDisk and retained between reboots. Desktops with a personal vDisk cannot be shared between multiple users; each user requires their own desktop. If high availability is required, the personal vDisk must be stored on shared storage.

• Remote PC – Physical desktops that have already been deployed. These desktops must be managed manually or with 3rd party desktop management tools.

• Streamed VHD – Desktops are based on a single master image and provisioned using Provisioning Services. The streamed VHD FlexCast model allows Windows XP, 7 and 8 desktops to be run locally on the user’s desktop computer. Streamed VHD is a great solution for high-end workstations because it allows them to leverage local processing power. Streamed VHD requires a LAN connection to be in place between the desktop and the provisioning servers and changes to the desktops are lost upon

reboot.

• Local VM – Windows XP, 7, and 8 desktops running locally within a hypervisor. The virtual desktop image is completely delivered to the hypervisor to allow for offline connectivity. Citrix XenClient is used to provide the Local VM FlexCast model.

• On demand apps – The On-Demand Apps FlexCast model does not provide users with a virtual desktop; instead Windows applications are centralized in the datacenter, and instantly delivered via a high-speed protocol (requires connection) or streamed (offline support) via Microsoft App-V.

FlexCast Model Comparison

Each user group in the User Segmentation worksheet should be compared against the following table to determine which FlexCast Model should be assigned. Ensure that you update the FlexCast

value for each user group in the worksheet.

Note: Any FlexCast decisions need to factor in latency. Please see the Latency section of the Design Phase.