Virtual Desktop infrastructure
The success of server virtualization in AdCom as well as across the industry has spawned a movement to extend these successes to the desktop PC environment. We are excited about the many potentially far-ranging benefits of such an environment, and have begun examining its feasibility.
Possible benefits include:
- Security
- Thin clients are stateless and store no data of any kind.
- All session data is encrypted RC4/128 (possibly TLS). Software client sessions are also SSL enabled.
- RSA SecurID 2-factor authentication is available
- With proper architecture, client VM-to-resource traffic can be kept on an internal network, since that traffic doesn't go to the end user.
- Unused sessions can be suspended and disconnected from the network
- Disaster recovery
- Possible to use virtual server BC/DR techniques to desktop VMs, including full-VM copies, storage replication. Doesn't require imaging of full PCs to use.
- Scalability
- Adding users and increasing client workloads are handled centrally and dynamically at the servers. Client devices do not change.
- Reliability
- No moving parts at client.
- Server hardware is inherently more reliable and is run in a controlled environment
- Availability
- Overall environment should be designed to minimize single points of failure
- Compatibility
- Standard desktop OS means no software incompatibilities
- Upgradability
- Server upgrades can be done with no downtime. Client VM upgrades can be done in parallel to working client VMs. Endpoint devices are stateless so are easy to upgrade.
- Performance
- CPU/memory/disk/network performance should be equal better due to improved hardware and consolidation efficiencies.
- Remote accessibility
- User sessions/data not tied to any endpoint device. Can be accessed from any compatible web client, or any client device within the environment without loss of (active) session data
- Manageability
- All OS/app/data operations being performed centrally will decrease management efforts in all areas, including patching, utilization, troubleshooting, etc.
- Limiting changes to user experience
- Standard desktop OS means familiar user experience. Ability to import existing environment directly.
- User session continuity
- Sessions are endpoint-device independent, so they follow the user
- Energy savings
- 75w net savings per user. More if dynamic server power management is implemented
- 110BTU/hr heat dissipation decrease
- (long-term) Capital cost reduction
- Disposal
- e-waste: 15lb per unit
- packaging: 3lb per unit
Possible drawbacks are:
- Initial capital cost
- Optimal implementation requires significant server-side infrastructure, including servers, storage, network and related infrastructure. Also few opportunities of reusing existing desktop PCs.
- Software licensing issues
- Some software ISVs have licensing policies not conducive to virtual environments (per CPU, OEM agreements, etc.)
- Performance
- Reliant on reliable and low-latency connectivity to deliver to end client
- Motion graphic-intensive workloads are less suitable
- Under-sized infrastructure can lead to decreased performance for many users simultaneously due to shared, consolidated architecture
- Insufficient support/performance for some desktop peripherals (high-speed storage, graphic-intensive devices)
- Off-line use
- Due to the need for network connectivity to the VM, off-site use where there is little or no network connectivity is not feasible.
Performance and off-line issues are key issues that are actively being targeted by the industry. Upcoming upgrades are intended to help address many of these issues.