The Tru Linux Story - Linux-Migration bei Hilti

Due to HP's decision to discontinue the Alpha architecture and Tru64 UNIX the question a rise for the Hilti Corporation, which platform the strategic SAP systems should be migrated to.
Despite the warnings of all consulted hardware manufacturers, the decision fell on industry standard x86_64 (X64) servers on Linux. Although it was common knowledge at this time that performance of the largest available X64 servers would not be sufficient for our large systems, we trusted however in the fact that this would change up to the migration of these systems in Q2/2009.
Although internally only experience with SuSE was present, Red Hat was elected to become our strategic OS. This decision was based mainly on Red Hat's strong focus on Enterprise Systems and the availability of a matured cluster file system GFS and HA cluster framework. Atix's consulting solution 'Diskless Shared Root Cluster' further on promised the opportunity to keep the 'TruCluster Feeling' available under Linux. Particularly the concept of a common root file system for all cluster nodes was a major feature, that we did not want to give up.
The Presentation will highlight the path from decision-making up to the successful implementation without ignoring the problems.
Actually we run about 160 Linux servers under RHEL 4. Lot of them as 'Diskless Shared Root Clusters' with up to six nodes. In 2006 we begin with 80 servers add in the second Rollout arround another 80 Servers. Our 'entry level' server was a HP DL585 G1 with 16GB RAM and two dual core CPUs, the high end systems are currently HP DL785 in a maximum configuration (128GB RAM, 8 quad core CPUs). Storage-wise, we use up to 14TB on one single  cluster, whereby all file systems are shared on GFS. We have a multivendor Strategy Server and Storage-wise.