The humming sound reminds you of an airconditioned hotel room in Hawaii – except it’s quite a lot louder. André Bögelsack is not on vacation, however; he’s at work. Once again, he’s had to make his way down to the small, windowless basement room to sort out a problem. This is where the SAP UCC at the Technical University of Munich houses its servers – and one of them is refusing to boot up. Bögelsack wants to fix the problem right away, otherwise the UCC administrator and his colleagues will be inundated with phone calls from customers that might not be able to use their SAP systems for training courses, lectures, or research work. In the basement, Bögelsack pulls a hard disk from the defective server and slots it into the server directly below.
All he needs to do now, presumably, is switch the cables to be back in business. “Switch the cables? We don’t do that anymore,” says Bögelsack, recalling his early days at the UCC. Today, he manages this mini data center – whose 50 servers run 120 SAP systems – from his laptop. It is more out of habit than necessity that he trots down to the basement once a day to “see how my babies are doing.” The fact that Bögelsack can take a relaxed turn around the basement is due to an infrastructure that relies entirely on virtualization – and lowers costs for everyone involved.
The virtualization era
When the UCC started operation in 2003, it ran one of Germany’s largest Sun Blade server installations. In 2005, Sun launched the Solaris 10 operating system. The servers were more powerful and could accommodate four or five SAP systems rather than just one. Then, at the end of 2006, Sun brought out Release 11/06 of Solaris 10 and introduced the “zone” concept. This was the beginning of the virtualization era at the UCC.
Zones operate as completely isolated containers that allow operating systems and applications to be virtualized. Each Solaris 10 system includes at least one defined zone, known as the global zone. This zone contains the operating system kernel and the main server services, and is where most of the administrative activities take place.
A global zone can host up to 8,192 local zones. These are completely separate from each other, thus providing a high degree of security. For virtualization experts, the Sun zone concept is an example of operating system partitioning. Using the Solaris Resource Manager, the required capacities can be dynamically assigned to the relevant zones. At the UCC, the SAP systems run in local zones: one local zone for each part of an SAP system. Each SAP system or part of one can be maintained and restarted independently of the other systems on the same host, and that one zone can be moved to another server. “We can almost completely eliminate downtime,” says Bögelsack. “We’re also a lot more flexible and can respond quickly to whatever requirements our customers have.”
As an example, the training program at an affiliated university advertises a course on Tuesday mornings at which students can practice managing an SAP business intelligence solution based on case studies. When the 20 students simultaneously activate an InfoCube, the zone on which the SAP system is running on the UCC server has to work flat out. The Sun infrastructure comes to the rescue by powering up any extra capacity that is required.
SAP University Alliances Program
Even on Saturdays, there is no let-up for the UCC servers. On that day, students like to work through what they’ve learned during the week. In addition, many universities hold block seminars lasting several hours. “These peak-load periods alternate with periods when the servers aren’t needed at all,” says Bögelsack. “Virtualization helps us absorb the peak times by dynamically distributing resources without having to constantly buy more hardware.”
With more and more universities looking to profit from the services of the UCC, additional servers would normally have been required long ago. “We are growing with the success of SAP and the SAP University Alliances Program,” says Helmut Krcmar, professor of business informatics at the Technical University of Munich and head of the UCC. But the UCC can’t just keep buying new hardware. Krcmar explains: “Virtualization is our way of dealing with growth.”
The UCC now has some 100 virtual machines running on just 21 servers – and the degree of virtualization is increasing. This enables the UCC to quickly link up new universities to its network without having to wait weeks for new hardware. What’s more, there is aöso a reduction in what Krcmar calls “disk space waste”: Thanks to virtualization, the hard disks in the UCC data center are run at almost full capacity. “This is a key cost argument for us and for our customers.” Before storage virtualization was implemented, only the disk space directly connected to a server could be used: Only one server could benefit from the available disk space. In the virtualized environment, all the servers can profit from it.
The UCC’s customers benefit in another way from its virtualization initiatives. UCC employees conduct ongoing research into how Sun and SAP can increasingly profit from each other through studying virtualization, and how virtualization solutions can help improve capacity use in complex SAP landscapes. As Krcmar says: “We can conduct research on a very practical level here. This benefits hardware and software vendors and enables us to increase the quality of the training we offer for lecturers and students.”
UCC administrator Bögelsack has also learned a great deal in recent years. Without virtualization, it would be almost impossible for him to manage the hardware in the UCC data center singlehandedly. And if he suddenly yearns for the experience of a hotel room in Hawaii, he only has to pop down to the basement.