Virtualization of the SAP environment with Duisburger Versorgungs- und Verkehrsgesellschaft mbH (DVV)
Du-IT Gesellschaft für Informationstechnologie Duisburg mbH is the leading provider for IT services in Duisburg. The credo of the 180 employees is clearly defined: honesty, reliability, and professionalism are the key components of the successful work performed by Du-IT in the customer segments of supply and disposal, mobility, service providing and municipal entities. Du-IT is the leading provider of IT services in and for the city of Duisburg, its subsidiaries and other
municipal customers.
Consolidation and virtualization of the SAP environment with Duisburger Versorgungs- und Verkehrsgesellschaft mbH (DVV) based on the Hitachi Converged Compute Platform
IT infrastructure
The area of IT infrastructure is being lead by Stefan Soldat and among others offers also the operation of data centers in the locations of Duisburg and Krefeld, as well as installation, maintenance, operation and providing of centralized and de-centralized IT infrastructure for the customers of Du-IT, application providing, IT services for the business areas of Du-IT as well as support in setting up and operating SAP systems.
ERP/SAP applications
The area of ERP applications of Du-IT, which is being lead by Thomas Steinbach, encompasses SAP industry solutions and SAP applications for accounting, human resources, logistics and the SAP basic technology. The business are of ERP applications offers this to the customer segments mentioned above: supply and disposal, mobility, service providing and municipal
financial management and public transportation.
Initial situation
Prior to consolidating the SAP Environment through the virtualization of the IT infrastructure the situation was the following: The SAP infrastructure had only one data centre location. Both the productive system and the quality assurance system were running on the same hardware. When the productive system failed, the quality assurance system was used instead. A limited resilience was the consequence, limited scalability as well as issues with performance peaks and a lack of project operation added to unbearable constraints.
Goals and considerations
The further planning was driven by technical as well as commercial factors equally. For Marco Undank, responsible for the SAP infrastructure of the IT, a hardware-based high availability scenario was the major criteria. „The SAP applications have to be installed, managed and operated as easily as possible. A software cluster, despite the target of a failover between two locations, was out of the question.“
In addition to that operating restore within four hours had to be guaranteed and switching off one data centre should not entail any restriction for the operating use. Starting with these requirements Du-IT evaluated and tested different service providers and infrastructure scenarios. In the end Hitachi Data Systems was closest to the expectations of Du-IT in offering SAP certified Compute Blades (new in Europe) with LPAR virtualization taken from the mainframes together with the n+m Failover.
Server and storage virtualization with Hitachi Converged Compute Platform
Based on the Hitachi Mainframe technology the newly developed Hitachi Computer Blades are being sold in Japan for 6 years and a market leaders next to, respectively ahead of HP and IBM in the home market of the vendor. Being the biggest SAP sales partner, respectively integrator, Hitachi additionally dominates the area of SAP applications in the land of the rising sun. Combined with the high performance storage systems of Hitachi Data Systems this leads to a
Converged Compute Platform for SAP applications, that offers new technical and economic advantages.
n+m Failover
The n+m Failover integrated into the Hitachi Blades excellently covered Du-IT‘s requirement of a close to hardware high availability scenario without software cluster. Comparable to spare drives in storage, these offer a freely selectable number of additional „n“ blade servers to be defined as „cold standby“ without additional license fees for an also freely selectable number of production blades, that can be replaced by one of the standby blades when needed. This works in chassis hardware as well as rack hardware or as in the example of Du-IT encompassing locations and thus saving on cluster software and superfluous hardware that would otherwise be needed for a 1+1 or n+1 cluster.
Hitachi Virtualization Manager (HVM)
Coming from the mainframes the LPAR technology together with the Hitachi Virtualization Manager (HVM) additionally offer a server virtualization close to the hardware that enables direct access to server peripherals and host bus adaptors while supporting derivative file systems on Windows and Linux. This saves users not only license costs for the virtualization software, it also
circumvents the virtualization layer with its proprietary file systems and offers performance and security advantages for the operation of high performance and critical applications and database applications. At the same time all Hitachi Compute Blades are certified for VMware and Hyper-V, so that they can be used in all leading HyperVisor and also the Hitachi Virtualization Manager (HVM) anytime.
LPAR technology and dynamic respectively dedicated resource sharing
Another advantage of the Hitachi Blades for DU-IT was the possibilities of resource sharing that are offered by the Compute Blades based on the LPAR technology. By using this CPUs and memory can be assigned to the logical partitions (LPARs), virtual instances or applications in a dynamic or in a dedicated way, even combined.
This does not only increase performance and security of applications and database applications, it also allows for an strongly improved usage of the server hardware, which in turn reduces the investment and operating costs further. The energy saving functions of the Hitachi Servers and the performance and I/O ratios being optimized for Hitachi Storage Systems combined result in significant and sustainable cost/benefit ratios for failsafe SAP operations.
Thomas Warthun, responsible for storage at Du-IT, states from experience: „Even in full usage the LPAR virtual instances show a hardware usage of the Blades of hardly above 35%.“
This is only one of the reasons why Du-IT is going to migrate additional and so in total significantly many more virtual Servers to the existing Compute Blades compared to the original plans.
Implementation of the SAP virtualization
In many IT projects not all goes as planned nor flawlessly. Despite that it has to be stated that in retrospective of all people involved the consolidation and virtualization of the SAP environment of Du-IT was surprisingly smooth.
Integration into the network
Initially there were problems with the network. Stefan Gatz, network specialist in charge at Du-IT, reports: „after the integration of the Compute Blades there was a multitude of broadcast messages that had a negative impact on the network performance. Most likely too many open ports were the cause for that, which is why we have switched off some of the network cards in the servers.“ The performance of the network thus was stabilized again. To reduce the number of ports, currently the use of 10GB ethernet cards is being tested. This is one of two changes compared to the technical plan. Due to the performance of the Hitachi Blades not only SAP servers but also other virtual servers can be migrated onto the existing Hitachi Blades.
SAP sizing and planning
The planning phase and the sizing of the virtual SAP infrastructure through Green Data Systems as SAP infrastructure partner have been used intensively in this project. „Thanks to the good preparation and planning of the SAP virtualization project, the implementation could be finished in three months successfully,“ says Ulrich Elischewski, team leader IT infrastructure at Du-IT. „At the same time the planned short downtime was used to successfully change from Windows 2003 to Windows 2008 R2.“
One outage
The only hardware outage since the Installation of the Hitachi Converged Computer Platform in summer 2011 was a defective fibre channel adaptor, which could have been replaced easily thanks to the n+m Failover concept. The spare blade that has been taken into operation to replace the outage is in productive use since, while the blade with the defective FC adaptor now serves as a spare server with a replace fibre channel card.
Results and savings
„By using Hitachi Computer Blades SAP systems can be set up as large central instances very well, so that administration
is easy also for standby teams,“ states Marco Undank, and Thomas Warthun adds: „The LPAR concept requires a
change in the configuration and handling, you can see the mainframe concept, yet it offers excellent scalability, high
security and good usage for the servers.“
Du-IT currently operates 66 virtual SAP servers, 24 in the production site in Duisburg and 42 in the project respectively quality assurance site in Krefeld. The distance in-between for the n+m site failover of the Hitachi Compute Blades is 34 kilometers.
„By virtualizing the infrastructure we only need one blade chassis with 3 Hitachi Compute Blades to virtualize 66 SAP servers per data centre location, 2 active and 1 that acts as a cold standby Blade for the failover between locations,“ summarizes Ulrich Elischewski.
And Stefan Soldat draws a positive conclusion: „60U less space required, more than
25% energy savings and approximately another 25% savings in license costs are a clear statement. We have also optimized on the availability across two locations and simplified the management and administration of our SAP environment significantly.“
Subject to be changed without prior notice. All pictures and graphics are samples, actual configuration may vary.
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