TDS AG is an IT services provider based in Neckarsulm, Germany, that provides consulting and outsourcing services, application hosting, and HR services.

A few years ago, TDS’s storage situation was in disarray. For one, the company did not have a SAN. “The storage infrastructure of our data centres was unstructured,” says Klaus Zimmermann, TDS’s head of data-centre services.

“The existing switches acted more like multi-sockets rather than a genuine network, and the storage-on-
demand model did not offer sufficient flexibility. We were dependent on one vendor.”

A particularly restrictive factor was the difficulty of rapidly responding to the growing storage demand. And only a few employees on Zimmermann’s team were capable of administering the monolithic disk arrays.

The goal became clear: To operate the data centres more cost-efficiently would require a complete revamp of the entire storage environment. “On one hand, we needed to become more flexible in terms of future extensions of storage
allocated to individual systems, as well as beyond the confines of the data centres,” says Zimmermann. “On the other hand, we urgently needed to become
independent of one vendor or technology for these extensions.”

Further requirements of the new architecture included a future-oriented design and the deployment of new technologies to reduce the costs of direct-attached storage and associated costs such as SAN management and data backup. It became clear that these changes could only be realised with disk-based storage virtualisation.

The solution

Virtualisation splits up the storage into a physical implementation layer and a logical representation layer by means of the abstraction of physical to virtual storage. This creates a “storage pool” that can be divided up, extended, and adapted flexibly. After evaluating a number of virtualisation options, TDS opted for the LSI StoreAge SVM platform. This also entailed restructuring the data centres on the SAN hardware level to obtain optimum price and performance.

The first implementation phase was in the area of the storage hardware. Next was the deployment of StoreAge’s virtualisation platform. At the same time, Zimmermann was aware that a project such as this would be very time consuming and complex.

“Installing a completely new SAN infrastructure was not possible in a single step,” Zimmerman explains. “We had to convert our IT infrastructure in a number of phases to exploit all the advantages of virtualisation. We opted for SVM appliances because their functionality enabled us to achieve most of our goals.” The SVM is based on “split-path” technology.

TDS also attached importance to other criteria, including support for a wide range of operating systems and RAID arrays from different vendors.

The virtualisation appliances provide a variety of functions. For example, they provide volume management and snapshot functionality via LSI’s multiView software. LSI also uses dynamic storage allocation for its low-capacity snapshots. It is possible to generate physical copies of volumes using multiCopy, while multiMigrate provides any-to-any data migration services, irrespective of the storage hardware. Also, TDS uses multiMirror for synchronous and asynchronous mirroring, both locally and remotely.

“Thanks to virtualisation, we were able to optimise the storage network without restrictions in performance,” says Zimmermann. “Centralised management also facilitates individual storage processes.”

Small steps

The overall project was divided into three phases. In the first phase, the focus was on testing several options. The following year, TDS selected the LSI StoreAge SVM platform. After that, installation and data migration began. The four-year project was completed near the end of last year.

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A pair of SVM appliances is located in each of TDS’s three data centres, where they centralise the storage management. Seven new HP EVA5000 systems and six Brocade SilkWorm 24000 directors have been added. In total, Zimmermann manages 21 HP EVAs, five EMC Clariion 700 arrays, and eight SilkWorm 24000 directors in nine SVM domains. These components can be virtualised, controlled, and managed via the SVM.

“Our data centres barely resemble their initial state,” says Zimmermann. “The new concept is working out, and the restructuring has been a success for us.”

Centralised, consolidated

“As you might expect, we encountered problems along the way over the four years,” says Zimmermann. “With such a major project, difficulties are inevitable. However, the advantages we gained with the new SAN confirm that we made the right decision.”

Centralisation and consolidation of the hardware facilitates storage/server management. Currently, the network has about 1,100 SAN ports, nine SVM domains, 2,500 hosts (500 of them in the SAN), and 3,100 volumes. These volumes can be managed using the virtualisation appliances by any member of the IT team.

Further advantages for TDS include low latency, flexibility, and a centralised SAN reporting facility. Storage services are now available without being restricted to specific vendors or the confines of data centres. As a result of using different storage classes, implemented in the form of various Fibre Channel and SATA drives, the company has implemented a cost-efficient tiered architecture.

TDS plans to further automate work processes and to optimise management functions. At a later stage, LSI’s SVM technology will be integrated with existing TDS tools.

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At-a-glance

Challenges

• Requirement for structured and scalable storage infrastructure
• Need for vendor independence
• Need for more cost-effective data- centre management

Solution