Addressing the challenges of application and desktop virtualization (part 2)

In the third part of a 4-part series Better Virtualisation with Citrix — Addressing the challenges of application and desktop virtualization (part 1) — we have discussed how XenSever helps ultilising hardware performance and simplify management process. In this final part, we will see how the combination of Citrix XenApp, XenDesktop and XenSever can makes virtualization simple and economically feasible.

Application availability

XenServer premium editions features—such as workload balancing, high availability, live migration and site recovery—make it simple for IT to provide users with a more resilient and highly available infrastructure than with physical servers. These capabilities help businesses achieve a more agile and responsive IT infrastructure and solve disaster recovery and application availability challenges.

desktop virtualization

Leveraging XenServer with XenApp or XenDesktop can minimize the impacts of hardware maintenance on application uptime and availability by allowing for real-time maintenance. For example, if IT needs to replace a hardware module in a server, it must typically schedule a maintenance window and power down servers during which the applications and user sessions running on that server are interrupted. Since virtualization separates the application from the hardware, customers can leverage XenMotion, the live migration feature of XenServer, to eliminate planned downtime by migrating actively running VMs from one physical server to another without interruption. As a result, XenApp servers and applications remain running even if an entire server is taken down, enabling zero-downtime maintenance. Live migrations of XenApp virtual servers are seamless: they can be initiated via a simple drag-and-drop operation or command and do not impact the user or the running applications.

The premium editions of XenServer all include high availability for VMs and third-party options for continuous fault tolerant operation, making XenApp and XenDesktop environments highly available. A VM and its associated workloads can be restarted automatically on another physical host should the original host fail. Thus, if the host experiences a failure, all the XenApp or XenDesktop VMs residing on that host will automatically start elsewhere in the resource pool. Extending this benefit is workload balancing (WLB). WLB allows VMs to be dynamically moved within the resource pool based on application requirements and host utilization. Should a XenApp or XenDesktop VM be constrained by demand from other applications running in VMs on the same host, XenMotion can automatically move the VMs to other hosts in the pool. In this way, customers can optimize application performance and ensure that service levels are always met.

Finally, the Site Recovery feature of XenServer helps organizations streamline their approach to disaster recovery (DR) for XenApp or XenDesktop workloads. Site Recovery enables IT to rapidly transfer XenApp and XenDesktop workloads and applications from a primary datacenter to a DR site as part of a simple business process. In addition to coordinating replication, Site Recovery also allows IT to implement the DR plan with just a few clicks. This operation includes booting the secondary environment, switching services and ultimately failing back services once the primary site is back online. By leveraging Citrix® StorageLink™ with Site Recovery, IT organizations can shift applications from one site to another in minutes using a fraction of the physical infrastructure at the disaster recovery site while leveraging their existing advanced storage management software.

Better together – 1 + 1 = 3

While other server virtualization solutions offer similar capabilities, XenServer is uniquely capable for hosting XenApp and XenDesktop workloads. The XenServer platform delivers best in class performance for XenApp and XenDesktop workloads (as well as for other Citrix workloads such as Citrix® NetScaler® VPX). The XenServer performance advantage helps customers reduce both capital and operational costs, which are critical to successful desktop and application virtualization deployments.

These performance benefits have been documented internally as well as through independent third-party testing. The most recent Virtual Reality Check (VRC) testing by Log In Consultants found that XenServer was the clear performance leader—especially when leveraging hardware technologies such as hyper threading. Using hyper threading along with XenServer to host XenDesktop and XenApp workloads allows a system to host more users and deliver better response times. In one case, VRC found that XenServer offered a 20 percent performance advantage over other leading virtualization platforms. Citrix internal testing confirmed these findings. Citrix tests used a similar methodology and found that XenServer could host more desktop VMs per server and boot more desktop VMs faster than any other server virtualization platform.

XenDesktop installations running on XenServer will require fewer servers, thereby reducing costs and improving ROI. Additionally, the more rapid boot time with XenServer means that employees using XenDesktop will experience faster application opens, which will improve user experience and productivity, reduce support calls and lower operational costs.

Citrix also delivers simple packaging and technology licensing. All automation capabilities are bundled into XenServer Platinum, rather than requiring the customer to purchase high value capabilities such as Site Recovery and Lab Manager as ala carte modules. Extra charges for core process automation technology add significant expense to any desktop or application virtualization project.

In addition, with XenServer, Citrix has committed to a transparent per-server licensing model, which means that with XenServer, upgrading hardware (for example, when processor manufacturers add cores to processors and server OEMs add processors to servers) will not drive up virtual software costs as it will with other leading vendors. By committing to licensing at the server, Citrix delivers more value and predictability to licensing costs—which most organizations find extremely important.

Conclusion

Citrix XenServer makes virtualization simple and economically feasible for both Citrix XenApp and Citrix XenDesktop environments and other key infrastructure components. XenServer provides:

Consolidation for XenApp servers that optimizes use of servers to reduce costs
Simplified management that makes it easy to achieve flexible deployments, rapidly scale to meet application demands, and better manage and control test and development processes
Application availability for XenApp and XenDesktop with capabilities that minimize the impact of hardware maintenance on application uptime and availability, and streamline disaster recovery fail over and fail back

XenServer delivers best in class performance for XenApp and XenDesktop workloads, and customers achieve these benefits at half the cost of competitive solutions from VMware.

Source: Citrix's Blog

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