Changes to this message: Update Dear users of SuperMUC, it has turned out that the needed maintenance measures not onlv involve updates on the compute nodes, but also in the storage and configuration infrastructure. Therefore we have decided to postpone the maintenance, as well as to extend it from one to two days. Between October 29, 8:00 and October 30, 18:00 the system will therefore be unavailable for user operation. During this maintenance configuration changes and software updates will be installed which should improve stability of both Intel and IBM MPI operation. Particularly a memory leak in the IBM MPI library and some problem with MPIIO should be fixed. If we have recommended to you to use: MP_MPILIB=pempi and/or MP_SHARED_MEMORY=no we ask you to recompile, relink and rerun your application and check against the new library without these setting. An update for the GPFS file system will also be installed (although it is not expected that this update will solve all outstanding problems). This information is also available on our web server http://www.lrz-muenchen.de/services/compute/supermuc/aktuell/ali4438/ Reinhold Bader