Added Known Problems and Troubleshooting (splitted)

pages/merlin6/known-problems.md

@@ -0,0 +1,36 @@
+---
+title: Known Problems
+#tags:
+#keywords:
+last_updated: 20 June 2019
+#summary: ""
+sidebar: merlin6_sidebar
+permalink: /merlin6/known-problems.html
+---
+
+## Known Problems
+
+### Paraview, ANSYS and OpenGL
+
+Try to use X11(mesa) driver for Paraview and ANSYS instead of OpenGL:
+
+```bash
+# ANSYS
+module load ANSYS
+fluent -driver x11
+
+# ParaView
+module load paraview
+paraview --mesa
+```
+
+###+ Illegal instructions
+
+It may happened that your code, compiled on one machine will not be executed on another throwing exception like "(Illegal instruction)".
+Check (with "hostname" command) on which of the node you are and compare it with the names from first item. We observe few applications
+that can't be run on merlin-c-01..16 because of this problem (notice that these machines are more then 5 years old). Hint: you may
+choose the particular flavour of the machines for your slurm job, check the "--cores-per-node" option for sbatch:
+
+```bash
+sbatch --cores-per-socket=8 Script.sh # will filter the selection of the machine and exclude the oldest one, merlin-c-01..16
+```