Reconfigure Service Node MAMU

Describes how to reconfigure a MAMU service node as a compute node.

This procedure assumes the following:
  • The Cray XC system is booted.
  • MAMU (multiple application, multiple user) service nodes are configured on the Cray XC system.

The only way to increase or decrease the pool of MAMU nodes is to reconfigure it and reboot the system. The following procedure describes how to reconfigure a MAMU service node back to a compute node.

In the steps below, the example MAMU node that needs to be changed back to a compute node is called mamu10, which belongs to the mamu_nodes node group.

  1. Remove the host information for the MAMU service node in the cray_net config.
    smw:~ # CNAME=$(cfgset get cray_net.settings.hosts.data.mamu10.hostid p0)
smw:~ # echo $CNAME
smw:~ # cfgset modify --delete cray_net.settings.hosts.data.mamu10 p0
smw:~ # cfgset get cray_net.settings.hosts p0
  2. Remove the MAMU service node from the node group in cray_node_groups config in case Ansible plays take action on MAMU nodes.
    smw:~ # cfgset modify --remove $CNAME \
cray_node_groups.settings.groups.data.mamu_nodes.members p0
smw:~ # cfgset get cray_node_groups.settings.groups.data.mamu_nodes.members p0