When DRAGNET participates in an observation, COBALT is started first. The COBALT runObservation.sh script contacts storage nodes via ssh to run the outputProc binary.
COBALT storage cluster specific properties are sourced by runObservation.sh from cobalt_functions.sh.

To do the above, the following software and (non-default) system config items need to be in place:

  • A LOFAR software release on DRAGNET installed under /opt/lofar/ that matches the COBALT software release version the COBALT cluster
  • The cbmmaster node (thus cbt001) must be able to ssh as user lofarsys to all DRAGNET nodes non-interactively. This requires:
    • working infiniband network, hostnames, IPs, (default) routes
    • DRAGNET lofarsys private key (on lofarsys NFS homedir) also available on cbt001 (sync-ed on all COBALT nodes)
    • a user lofarsys .ssh/config file on cbt001 (sync-ed on all COBALT nodes) that deals with ssh hurdles. Currently (Aug 2017), this contains the following (among other lines) catering for all cases:
Host=dragnet dragnet.control.lofar dragproc dragproc-10g dragproc.control.lofar dragproc-10g.online.lofar drg?? drg??.control.lofar drg??-10g drg??-10g.online.lofar drg??-ib drg??-ib.dragnet.infiniband.lofar
  • Subsequently, rtcp processes on cbtXXX contact outputProc processes on storage nodes via tcp/ip.


  • Last modified: 2017-08-18 00:45
  • by amesfoort