Desktop as a Service (DaaS) is a cloud hosted Virtual Desktop Infrastructure (VDI) and has the potential to reduce the upfront costs and scaling issues associated with deploying virtual desktops. But these cloud hosted users still need to be able to connect back to the corporate data center to access data and other corporate resources. This leads to complex networking challenges and latencies as users work their way through corporate VPNs. It has the potential to eliminate much of the DaaS advantage.
VDI vs DaaS
DaaS has often been positioned as a competitor to VDI, but it should be looked at as a compliment, assuming the above storage challenge can be worked out. Like most cloud services, a big advantage for DaaS is minimal upfront investment. But an internal VDI project’s investment can be quickly offset if there are enough users and if it is designed in a way that users see the virtual desktop as a positive change. For internal VDI it is all about scaling the number of desktops per host and per storage system. The more desktops and the fewer hosts/storage systems the faster the upfront investment can be offset.
Connecting a cluster of users to a locally hosted virtual desktop environment provides the best chance at user acceptance. The low latency of a local LAN connection allows those users to feel like they are connected to a real physical desktop. Users don’t stay still anymore but thanks to almost ubiquitous 4G broadband and WiFi access, users can stay connected to their virtual instances, but is that connection useable? As the distance from the desktop host increases the latency in screen refreshes becomes more pronounced and users become dissatisfied. The worst situation is the remote office or temporary office where users have to suffer through high latency.
DaaS solves this problem by reducing latency and the number of network hops since users make one connection to the cloud provider which is where their desktop is hosted. As a result DaaS is ideal for remote or home users, temporary work locations and quickly on-boarding new users as the result of a merger or acquisition. The smaller the desktop concentration and the further away it is from the primary data center the more DaaS makes sense.
Ideally an organization should leverage both deployment models. VDI for situations where large clusters of users could be serviced by a VDI host server on a local network, and DaaS for situations where there is a small number of users or the location is temporary. The problem is that this mixed use case develops a new storage problem that needs to be solved; connecting cloud hosted users to data center hosted data and resources.
The Downsides of VDI in the Cloud
The challenge with DaaS, especially when the deployment is mixed with traditional VDI, is accessing and managing what is probably most important to users: their file data. File data is the data that users create like Word, Excel and PowerPoint documents but it might also include architectural and engineering drawings as well as audio and video files.
Another challenge is integrating these users into the organization’s directory services. Since the cloud is a stand alone silo of users, integrating them into the corporate infrastructure is difficult.
The primary workaround is to create a VPN tunnel from the cloud hosted virtual desktop to the data center. This adds back in the latency that was being eliminated by hosting the desktop in the cloud. It also creates complexity for both the users and administrators to make sure the VPN tunnels are operational.
A second workaround is more of a brute force approach. It involves copying data from corporate file servers into the cloud and then copying new or changed data back to the corporate file servers. This requires IT to manage replication and file versioning, and creates a potential security issue as corporate data is now in the cloud in an unsecured state.
The DaaS and VDI Solution
To solve this problem will require one of two approaches. The first is to move all corporate file serving assets to the cloud via a secure file server solution. The problem with this approach, other than the significant change in infrastructure, is that most of these services won’t allow the organization to control which cloud the data is stored in and where. Another challenge is that now all file data is in the cloud, which increases cloud costs.
A second solution is to have a global file system (GFS) that replicates data between internal data centers and multiple cloud providers. The cloud GFS would also enable organizations to leverage file locking and version control as well as encrypted access.
The debate over DaaS vs. VDI should come to an end. IT should be able to leverage both technologies as it makes sense to them. The key is resolving the file storage issue to make sure that DaaS based users can access corporate seamlessly without counting on complicated VPN connections. The good news is that solutions do exist as we will detail in upcoming briefing notes.