BwUniCluster2.0/Maintenance/2020-10

The following changes are planned for the maintenance interval starting on 06.10.2020 (Tuesday) at 10 AM and ending on 13.10.2020 (Tuesday) at 10 AM.

This information is still preliminary and subjected to change.

Operating system

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

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

• The Mellanox OFED InfiniBand Stack will be 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) will be 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 will be upgraded to GCC version 8.3.1 (from 4.8.5).

• The Intel compiler module versions will not change.

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

• The PGI Compiler will be updated to version 20.7 (from 19.1). It includes the NVIDIA environment in version 11.0 (e.g. nvcc).

• The system Python version will be 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 still used with the python2 command.

• The system Perl version will be upgraded to 5.26.

Development tools

• The default system version of the GNU Make build utility will be 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 autotools package will be upgraded to 2.69. The "devel/autotools/2.69" software module is no longer necessary and will be removed.

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

• The default system version of the Git version control utility will be upgraded to 2.18.4. The "devel/git/2.18.4" software module is no longer necessary and will be removed.

• Cent OS8's RPM now is case-insensitive, i.e. it will thread %VERSION% as %version followed by % -- this will lead to further errors; pre-defined RPM-macros should not be used in other contexts.

Userspace tools

• The screen utility is no longer be supported by Red Hat. The recommended replacement is tmux.

Batch system

• The Slurm version will be upgraded to the most recent minor version available at the start of the maintenance interval. At this moment this would be version 20.02.5 (instead of 20.02.3).

• 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 KDE Plasma desktop environment is no longer supported by Red Hat. start_vnc_desktop will default to GNOME 3.28 instead.

• The NVIDIA driver will be upgraded to the latest version available at the start of the maintenance interval.

Containers

• Network Namespaces will be disabled due to security concerns.