===== Observation to DRAGNET Startup Sequence =====
When DRAGNET participates in an observation, COBALT is started first. The COBALT [[https://svn.astron.nl/viewvc/LOFAR/trunk/RTCP/Cobalt/GPUProc/src/scripts/runObservation.sh?view=markup | runObservation.sh]] script contacts storage nodes via ssh to run the ''outputProc'' binary.\\
COBALT storage cluster specific properties are sourced by ''runObservation.sh'' from [[https://svn.astron.nl/viewvc/LOFAR/trunk/RTCP/Cobalt/GPUProc/src/scripts/cobalt_functions.sh?view=markup | cobalt_functions.sh]].


==== DRAGNET for Storage only ====
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
      StrictHostKeyChecking=no
      IdentityFile=~/.ssh/id_rsa_dragnet
      ForwardX11=no

  * Subsequently, ''rtcp'' processes on cbtXXX contact ''outputProc'' processes on storage nodes via tcp/ip.


==== DRAGNET for Correlation & Beamforming ====
N/A