Merge pull request #81 from stackhpc/feature/realmemory

Default node memory for slurm.conf now set from ansible facts

Author: sjpb

README.md

@@ -42,7 +42,7 @@ package in the image.
   Otherwise, `groups` can be omitted and the following attributes can be defined in the partition object:
   * `name`: The name of the nodes within this group.
   * `cluster_name`: Optional.  An override for the top-level definition `openhpc_cluster_name`.
-  * `ram_mb`: Optional.  The physical RAM available in each server of this group ([slurm.conf](https://slurm.schedmd.com/slurm.conf.html) parameter `RealMemory`). This is set to the Slurm default of `1` if not defined.
+  * `ram_mb`: Optional.  The physical RAM available in each server of this group ([slurm.conf](https://slurm.schedmd.com/slurm.conf.html) parameter `RealMemory`) in MiB. This is set to the total real memory from ansible facts if not defined (equivalent to `free --mebi` total).
 
   For each group (if used) or partition there must be an ansible inventory group `<cluster_name>_<group_name>`, with all nodes in this inventory group added to the group/partition. Note that:
   - Nodes may have arbitrary hostnames but these should be lowercase to avoid a mismatch between inventory and actual hostname.

templates/slurm.conf.j2

@@ -115,7 +115,7 @@ Epilog=/etc/slurm/slurm.epilog.clean
             {% set first_host_hv = hostvars[first_host] %}
 
 NodeName=DEFAULT State=UNKNOWN \
-    RealMemory={% if 'ram_mb' in group %}{{group.ram_mb}}{% else %}1{% endif %} \
+    RealMemory={% if 'ram_mb' in group %}{{group.ram_mb}}{% else %}{{ first_host_hv['ansible_memory_mb']['real']['total'] }}{% endif %} \
     Sockets={{first_host_hv['ansible_processor_count']}} \
     CoresPerSocket={{first_host_hv['ansible_processor_cores']}} \
     ThreadsPerCore={{first_host_hv['ansible_processor_threads_per_core']}}