BwUniCluster2.0/Maintenance/2020-10

The following changes are planned for the maintenance interval starting on 06.10.2020 (Tuesday) and ending on 13.10.2020 (Tuesday).

This information is still preliminary and subjected to change.

Operating system

• The operating system version is upgraded to Red Hat Enterprise Linux (RHEL) 8.2. We recommend to re-compile all applications after the upgrade.

• The Linux kernel version is upgraded to 4.18 (from 3.10).

• The Mellanox OFED InfiniBand Stack is upgraded to version 4.9 (from 4.7). If you maintain libraries which directly link against OFED libraried (e.g. MPI or PGAS libraries compiled in your $HOME directory) we recommend to re-compile these libraries after the upgrade.

Compilers, Libaries and Runtime Environments

• The GNU C Library (glibc) is upgraded to version 2.28 (from 2.17). This version will no longer automatically print backtraces after stack checking failures due to security hardening, which might affect the debugging of applications.

• The default system compiler is upgraded to GCC version 8.3.1 (from 4.8.5).

• The Intel compiler modules will not change.

• The Clang 8 module will probably be replaced in favor of Clang 10. The final decision has not been made yet. Clang 9 will continue to be available in any case.

• The system Python version is upgraded to 3.6. If no other Python module is loaded, the python command will default to Python 3.6, while Python 2.7 can be used with the python2 command.

• The system Perl version is upgraded to 5.26.

Development tools

• The default system version of the GNU Make build utility is upgraded to 4.2.1. Please note the new --output-sync command line option that allows better debugging of parallel builds.

• The default system version of the CMake build system is upgraded to 3.11.

• The default system version of the Git version control utility is upgraded to 2.18.

Userspace tools

• The screen utility is no longer supported. The recommended replacement is tmux.

Batch system

• The maximum total number of jobs of a single user in all queues (running and waiting) will be reduced to 100 (from 200).

Graphics stack

• The K Desktop Environment (KDE) is no longer supported. start_vnc_desktop will default to GNOME 3.28 instead.