SK Telecom builds a successful cloud service with Citrix XenServer

SK Telecom, founded in 1984, is a Korean telecommunications firm known for its leading edge technology that provides  the best voice-text service, content, applications and solutions for  improved productivity, communication and the convenient use of information. SK Telecom focuses on the deployment of wireless Internet services such as GXG and Mobile Cyworld, and new convergence services such as Satellite DMB, Telematics, Digital Home and M-Finance. SK Telecom is making strong efforts to advance into new business areas that combine wired and wireless services, such as MelOn and Cizle, and  is poised to lead the creation of innovative mobile lifestyles through its expertise in telecommunications.

Searching for ways to promote the development of new services

SK Telecom needed to develop a platform to support the service development environment for its mobile content partners. . The existing  partners had to build a development server and commercial service separately in order to develop new services, and they had to spend a lot of money and resources on hardware and applications. SK Telecom decided to build a cloud environment for its partners with a PaaS (Platform as a Service) format based on virtualization technology, the first company in the industry to do so.

Sung Bin Lim, a manager in the Data Network Headquarters of SK Telecom, who is in charge of this project explained, “The development companies had to purchase resources such as development servers and applications in order to realize their ideas; this was expensive, time-consuming.  and inefficient. We decided to implement  a PaaS cloud in order to develop services without having to worry about building  a platform.”

The PaaS  cloud  does not require partner companies to build separate services development environments   with servers, storage, network and applications. It is a service for requesting resources and making them available for use in the cloud environment provided by SK Telecom. Thus, it is a format for allowing the use of the service as needed, similar to a utility service such as electricity.

Introduction of Citrix XenServer optimized for cloud service

The important aspect for the PaaS  cloud computing  is to build a platform that can  provide a service development environment to make required resources and applications available for use. This is the reason why SK Telecom introduced Citrix® XenServer™, a server virtualization solution, for a flexible management of independent resources and efficient composition of server pool.

SK Telecom reviewed a variety of solutions including VMware  and Red Hat in addition to Citrix. SK Telecom’s top priorities were efficiency and function.  SK Telecom selected XenServer after considering function, stability and cost of implementation.

Lim said “We performed tests on Citrix XenServer along with other server virtualization solutions and selected Citrix XenServer considering its function, stability and efficiency. Also, the costs of implementation and hardware infrastructure investment for other companies were higher, but XenServer provided enterprise grade functions with relatively low implementation costs.”

Cost-effective and flexible resource management through XenServer

SK Telecom created a host OS hypervisor with XenServer that provides enterprise-grade functions and was able to efficiently use the virtualized resources required for building a cloud environment. SK Telecom has implemented about 80 physical servers by building 30 additional incubation systems that are currently operated in a test phase. Using the server virtualization technology of XenServer, up to about 600 virtual servers can be created from  80 physical servers (a 7.5:1 reduction ratio). SK Telecom is currently providing about 20 services using the cloud platform and plans to expand the number of services provided in the future.

The cloud platform has produced savings in  time, expense  and human resources previously needed for new service planning, resource request and resource allocation madepossible through the fast and efficient resource allocation of  virtualization technology.

Lim explained, “We are satisfied with the functions and features of Citrix XenServer. We are using resource management, monitoring and provisioning functions through the management tool XenServer. I’d assess the XenServer to have exceptional functions for the cost. In particular, it has the advantage of efficient and flexible management.”

SK Telecom has ultimately reinforced the partner ecosystem by introducing a cloud computing platform by using XenServer server virtualization technology, and it significantly increased the efficiency of time and resources needed for developing and commercializing the services of mobile service development partners. SK Telecom currently provides a cloud service internally but plans to expand this service to external content development partners in the future.

Grupo Martins Virtualizes Its Datacenter to Meet Future Demands in Wholesaling

Founded in 1953, Grupo Martins is the largest wholesaler-distributor in Latin America, marketing consumer items ranging from food products to electronics, construction materials, pharmaceuticals and veterinary products. Present in 5,570 cities throughout Brazil, Grupo Martins boasts annual sales exceeding R$4 billion and counts on around 315,000 active customers, 600 suppliers, 4,500 employees, 4,600 sales representatives and 42 operational branch offices.

The challenge: increase IT system availability for business process optimization

For Grupo Martins, like other large enterprises, finding new management tools and optimizing business processes are essential for reducing operational costs, ensuring customer satisfaction and achieving positive financial results.. Until 2007, Grupo Martins’ datacenter hosted 40 physical servers, which required significant space and power, as well as ongoing administration by the 30 professionals on its IT staff. Business content and applications critical to the company’s operations, including tools for telesales, long-distance training, e-commerce, network monitoring, and Internet, were installed on this server hardware.

To meet business requirements, it was paramount for the IT staff to deliver these server-based applications in a timely manner, which involved the demand for speedy creation of operating system environments or system configuration. “Physical servers have hardware components that are susceptible to problems. In case of a server’s unavailability, we would lose a whole day just to repair it and put the application back online or, in some critical cases, perform a total reinstallation on the machine,” said Flavio Lucio Borges Martins da Silva, CIO at Grupo Martins. This traditional approach required the availability of a back-up physical server, generating additional hardware and maintenance costs.

Moreover, high processing power was essential for each server in order to meet demands at peak usage times. However, aside from these peak periods, the servers’ utilization was only about 5 percent to 10 percent. “Our IT resources had a ‘retail’ demand during the better part of the month, with a peak ‘wholesale’ demand on certain days,” he explained. In addition, if demand rose higher than estimated, there was a risk that application performance would become sluggish.
Implementing Citrix XenServer to increase efficiency

In order to reduce underutilization of its servers and increase the availability of the datacenter, Grupo Martins replaced the older servers with newer equipment, comprised of seven physical servers running Citrix® XenServer™ virtual machines. The scope was expanded over the years and the latest change came in April 2008, when Grupo Martins acquired a license and implemented yet another solution from LCS—a Platinum Citrix Solution Advisor. Currently, the XenServer environment comprises 72 virtual machines running on seven physical servers and integrates four work platforms, which store all of the internal applications for telesales, e-commerce and assets control, the SQL Server® database and others.

Bringing more dynamism to the datacenter – and to business

Today, with Citrix XenServer, Grupo Martins has a more flexible datacenter. “Business is dynamic and throughout the month there’s a need for variable use of applications and resources to meet our employees’ needs,” explained the CIO. “With Citrix XenServer, applications and platforms are not tied down to the server hardware. If there is more demand for an application, the virtual machine can be rapidly moved to a server with higher available processing capacity. This flexibility allows the infrastructure to respond according to business demands and to eliminate slow performance in the system.”

The high availability of applications and servers is another advantage. He pointed out, “In case of a hardware failure on a physical server, the virtual machine is moved to another physical server and placed online in no more than three hours.” In the previous model, a dedicated back-up physical server was essential and the process could take up to a full day.

Virtualization to consolidate servers and reduce costs

Consolidation of physical equipment is one of the main advantages of server virtualization. “By reducing the number of physical servers from 40 down to seven, we have reduced costs of maintenance, space, renovation of the server farm, electricity and climate control, in addition to expanding the average utilization of equipment from 10 percent to 70 percent,” he highlighted.
Da Silva stressed that 80 percent of the servers created at the company are virtual. “Virtual machines are part of the Grupo Martins IT management culture because the time it takes to create one with XenServer is about 20 minutes.” Another facilitating factor is the accessibility of the solution.

Grupo Martins feels confident in continuing to expand its XenServer environment, because there are more than 70 Citrix Solution Advisors in Brazil who can offer expert services and support “Even though we implemented XenServer with Grupo Martins’ own IT staff, support from skilled Citrix channel partners will be crucial for more complex adoptions that will arise in the future,” Da Silva concluded.

With Citrix XenServer, applications and platforms are not tied down to the server hardware. If there is more demand for an application, the virtual machine can be rapidly moved to a server with higher available processing capacity. This flexibility allows the infrastructure to respond according to business demands and to eliminate slow performance in the system.

Flavio Lucio Borges Martins da Silva
Grupo Martins

XENIUM rescues server virtualization project with Citrix XenServer

Founded in 2002 and based in Wroclaw, Poland, XENIUM is a technology-centric developer and operator of complex web sites, portals, web applications and custom e-commerce solutions. A leading property in the XENIUM portfolio is Dobreprogramy—“good programs.” Dobreprogramy is the largest software and information technology site in Poland, and ranks among the top 10 Polish web sites overall with an audience of nearly six million users generating more than 40 million page views per month. XENIUM also publishes TechIT, a high-end web site for network administrators and systems engineers, and Gamikaze, a site targeted at the gaming and digital entertainment community.

Virtualizing Vyatta – VMware fails to keep up with demand

As an operator of several high-profile, high-traffic web sites, the performance and reliability of its network, systems and applications are top priorities for XENIUM. In its business, leaving users hanging because of inadequate system capacity, network congestion or the failure of any component in the end-to-end path—a situation that drives users away from rather than to sites—is simply unacceptable. XENIUM constantly looks for steps it can take to improve the performance and reliability of its web sites.

Like most organizations today, controlling costs is a major focus for XENIUM. The potential for improved reliability, and significantly reducing infrastructure and operating costs was the driving force behind the initiative by XENIUM to virtualize much of its computing environment.

“We saw server virtualization offering us several benefits,” explained Wojciech Kowasz, chief systems engineer at XENIUM. “Not only did it have the promise of reducing costs and complexity, but with features such as live migration we could also begin to work toward having our sites and services be more dynamic, more resilient—all without the need for operator intervention.”

The server virtualization product originally selected for this initiative was VMware® ESXi™ Single Server (now VMware vSphere Hypervisor) because it was free and because Xenium felt that ESXi had a more reliable track record of supporting Linux® workloads than Microsoft® Hyper-V™. This was a key requirement as XENIUM ran Vyatta, a software-based, open source network operating system, on Linux.

It wasn’t long, however, before XENIUM encountered a significant roadblock. As the XENIUM web sites steadily grew in popularity, the now virtualized instances of its BGP routers were unable to keep up with the greater traffic loads being generated. The latency for user sessions skyrocketed, as did the rate of packets being lost, even under relatively modest loads of 100 to 200 Mbps. Moreover, these issues were not limited to Vyatta. Other virtual machines running on the same host were also being impacted in the same negative manner. After several weeks of failed attempts to remedy the situation, XENIUM decided to move on and evaluate alternative server virtualization solutions. “Although we were in talks with Vyatta engineers and discussed the problems on VMware forums for weeks, we were unable to make the routers work correctly in the ESXi environment,” indicated Kowasz.

Migrating to XenServer – A stable solution with more features

XENIUM decided to test Citrix® XenServer® because it met their leading criteria of having a free edition and being able to support Vyatta on Linux. The results were everything they were looking for, and more.

  • Vyatta performance within the XenServer environment was stable at loads beyond those routinely encountered in production
  • The availability of a preconfigured virtual appliance for Vyatta saved time and effort that would otherwise be needed for installation and integration of associated components
  • Disk reads and access times averaged 10 to 15 percent faster than with ESXi, a seemingly small yet important gain for sites like Dobreprogramy which involve a lot of downloads
  • XenConvert, which automatically converts existing physical servers to virtual machines, worked flawlessly, enabling efficient conversion and automatic importation of Windows Server® 2008 virtual machines originally created for ESXi

Encouraged by these findings, XENIUM migrated from ESXi to XenServer quickly, without any issues and, most importantly, without any impact to ongoing operations. “Because we were migrating from one virtual environment to another, and because of the error-free operation of the XenServer virtual machine conversions tools, we were able to make the switch in a way that had no adverse impact on the quality and availability of our services,” stated Kowasz. It also greatly improved performance for their Vyatta routers.

XENIUM next took advantage of several features not offered by the version of ESXi they had been using (v4.0). “The first smile came when we saw XenCenter. We finally had the ability to manage all of our virtualized servers at once from a centralized, web management console,” noted Kowasz. Administration was further simplified and secured when authentication to its Active Directory domain was enabled.
The benefits kept coming. Because XenServer supports the Microsoft® VHD format for virtual machines—as opposed to the VMDK format required by VMware—administrators can mount related virtual appliances directly on their Windows® 7 notebooks or available Windows Servers®, a convenient ability in maintenance and troubleshooting. The presence of better monitoring and reporting tools than those available with ESXi was also cited as a significant advantage. “Both solutions are available in free flavors, but there is no doubt that Citrix XenServer provides many more features and options,” added Kowasz.

Looking to the future

The overwhelmingly positive experience with XenServer has XENIUM strongly considering how it can use XenServer more extensively. XenServer provides tremendous flexibility in this regard. To obtain functionality beyond that available with the free version, XENIUM can upgrade to a premium option at any time. The Advanced, Enterprise and Platinum editions of XenServer deliver progressively more powerful sets of management, integration, availability and automation capabilities. Features such as Citrix Provisioning Server help to further streamline IT operations and trim associated costs, while high availability, dynamic workload balancing and memory optimization pave the way to even higher levels of system reliability, application performance and overall efficiency. “With a consistent hardware configuration across all of our servers, we should be able to benefit from grouping them in a server pool and taking advantage of the available features to migrate workloads automatically, without the need for manual intervention,” said Kowasz. “Dynamic memory management available with the paid versions of XenServer looks very promising to us.”

Macau Polytechnic virtualizes next generation learning

Macau Polytechnic Institute is a government funded higher education establishment committed to providing student-centered education and training that combines rigorous learning with the excitement of discovery, promoting academic freedom, integrity and creativity. It supports a diverse research culture in a dynamic environment, and instills a spirit of service to improving society.

The institute’s IT facilities are a key instrument in the provision of advanced learning as well as the processing of data-intensive administration procedures. The institute is keen to build an IT infrastructure that incorporates the latest advances in technology and caters to the ever evolving needs of the individual faculties. It turned to Citrix to implement a dynamic virtualization solution that could consolidate applications with a state-of-the-art application delivery model that allowed secure access from any location.

A maze of applications

The institute has 22 computer laboratories across four campus locations, which provide over 1,500 computers for students to use. Each laboratory has a vast and varied number of applications according to the separate requirements of each faculty, e.g., the Art Faculty has many design-based applications such as Adobe® CS, while the Business School needs Microsoft® Office as well as analytics software such as SPSS. The university employed up to 33 applications, resulting in increased complexity and putting a huge strain on IT resources who have to continually manage and troubleshoot problems with the performance of the applications.

“The teachers of the individual faculties all have their own very different expectations on what software and applications are appropriate for them,” said Jose Chan, Head of IT at Macau Polytechnic Institute. “Of course our job is to accommodate their needs as much as possible so we needed to find a solution that could support a large number of applications as well as save storage space and staff resources.”

The IT department conducted considerable research to identify a solution that would work for the institute’s specific requirements. This included attending informative seminars and even trialing other vendor systems to obtain the latest information on how products and solutions could best serve them.

A concise application delivery infrastructure

Following an initial trial, the IT department opted for a Citrix end-to-end virtualization solution, which ultimately proved to be more effective than the incumbent VMware systems. The solution enabled the number of applications on local PCs to be cut by 75 per cent. The remaining applications now sit on back-end servers and use XenApp to streamline application delivery to individual PCs as required.

The complete Citrix end-to-end infrastructure, incorporating XenApp, Citrix® XenDesktop™ and Citrix® XenServer™, was the core component of the solution. A small pilot is currently being conducted in a private PC lab with a view to rolling out into public PC labs when testing is complete at the end of the year. The solution will then be rolled out through the computer labs and then through to the administration departments.

In total, the solution comprised 40 Citrix® XenDesktop™ 3.0, Advanced Edition and 40 Citrix® XenApp™ 5.0, Enterprise Edition solutions with three instances of Citrix® XenServer™ and three Citrix Essentials™ for XenServer™ 5.5 Enterprise Edition for deployment of 40 XenDesktop seats. The entire solution runs on just three IBM x3950 M2 physical servers with an IBM storage DS4700 disk system.

By virtualizing the server hardware, the university was able to consolidate the number of required servers into a smaller number of physical servers, optimizing the use of hardware resources. The high availability feature of XenServer offers zero fault tolerance for the entire solution without modifying the applications. XenDesktop enables user desktops to be moved from individual PCs into the datacenter, helping to prolong the PC lifecycle without compromising user satisfaction. In addition, the provisioning of new desktops can be accomplished with just a few simple clicks, freeing up resources to cater more dynamically and rapidly to user requests.

XenDesktop is proving to be an extremely valuable component of the end-to-end virtualization solution. Enabling PC users to access their own virtual desktop across any network or device simplifies the traditional desktop lifecycle. This is achieved by centralizing all virtual desktops in the datacenter, not on individual PCs, meaning that fewer physical resources are needed to install patches or security updates on to each PC—it can all be managed from the centralised datacenter. XenDesktop also allows students greater flexibility to access their own personalized dynamic desktop wherever they are—at the PC lab, in the library or even at home.

Citrix® HDX™ technology was implemented to deliver a blazing fast, high definition multimedia user experience that surpasses the speed of everyday desktops, regardless of the capabilities of the endpoint device.

“It didn’t take long to realize that the Citrix solution is exceptionally powerful and that it worked perfectly for us. Since installation, we have managed to reduce the number of applications on local PCs from 33 to 8. This is a great achievement and benefits our operations immensely. We will continue to implement Citrix solutions across the whole of the campus. Our end goal is to have a virtualized IT infrastructure across the entire campus. This facilitates not only remote learning for students but also enables teachers and administration staff to access the systems from any location.”


Minimizing the number of applications on individual PCs has brought the institute many immediate, tangible business benefits. Less complexity in the application infrastructure results in significant savings on IT implementation, system maintenance and technical support.

Consolidating applications on to back-end servers also results in less system downtime as IT staff only need to resolve issues at the server itself, rather than travel to a PC on location at another computer laboratory. This means they no longer have to focus on keeping applications running smoothly and have time to engage in more front-line support as well as adopt new technologies to further enhance the institute’s IT infrastructure for students, educators and administration staff alike.

“One of the key benefits has been the ability to centralize systems so we have fewer installations to maintain. This helps control application management and minimize support requirements,” said Chan.

The virtualized application delivery model is also highly scalable so it can easily accommodate future growth of the Polytechnic and its IT services. This will include increased capacity to support a broad variety of multimedia and IP-based features.

“Once we have implemented Citrix end-to-end virtualization solutions throughout the campus, we will have an ‘access anytime, anywhere’ environment. Teachers will be able to access teaching materials for lesson preparations in the comfort of their own homes, students can access critical resources remotely and administration staff can log in to servers from any location. We will have truly implemented a next-generation infrastructure,” said Chan.

An additional advantage to the application delivery model is increased environmental protection. Server consolidation has resulted in a reduction of 67 per cent of the servers across the 22 computer laboratories, resulting in reduced power consumption and a lower carbon footprint.

The entire system was remarkably easy to implement, taking only two weeks for full deployment. The institute was pleased with the simplicity and maturity of the solution, which accommodated its immediate and future business needs.

“The benefits have been enormous. In addition to minimizing IT support requirements and enabling greater application control, Citrix has enabled us to increase user satisfaction, reliability and increase manageability while simultaneously decreasing downtime and costs,” said Chan.

About XenServer

XenServer is the leading open source virtualization platform, powered by the Xen Project hypervisor and the XAPI toolstack. It is used in the world's largest clouds and enterprises.
Technical support for XenServer is available from Citrix.