4LT Farm and Data Logging

Author of this sheet: Jose Hernandez,
e-mail:  Jose.Hernandez@desy.de
Phone: office: 7224, mobile: 01704509401


    There is an l4aRobot process which normally runs on the logging node always and archives the files from the logging path   /hb/data*/REAL/...   to the tape path   /acs/data/REAL/... . It is steered with an old GUI which you can look at to learn the available tape space and logging disk occupancy, or use it if you'd like to restart the l4aRobot at some point.

Archiving troubleshooting

    Currently most of alarms coming from the Robot_Watch process, are due to poor robot responsiveness (to be fixed, mea culpa), and use to disappear themeslves. The only more or less important problem is when robot dies - then you can try to restart it from the GUI (to restart it, use preferably the latest GUI version from /afs/desy.de/group/hera-b/DATAMGR/dev/scripts/robot_gui_start (runnable on an hb-af machine) rather than that from the slow control).

  • Go to "Experts Only" and press "Start Robot".
  • If this does not work, try to remove first "/OTHER/l4aRobot" from namdir


    Please note (before disturbing the expert, I mean), that in the present set-up the disk space on hb4ltlog is large enough to keep running for ~12 hours at maximal logging rates.

    Also note that all the tape space to which we are writing, is monitored since mid of 2002 by the DESY Computer Centre, and more tapes is automatically added when needed. (The latest configuration was "a minimal count of 4 free tapes for the pool with 10 tapes increase if the minimal count is reached", where "1 tape" is ~20GB, the pools being checked each 4 hours.)

    But generally, in case of problems with archiving, communicate all of them to Dmitri Goloubkov: please call (x3587) or send him a short message on the 4LT s-call: (0)01681-9271945.

Related and unrelated links

DESY osm service page Hera-B tapes
The dCache online page

New documentation is being prepared.
No regular checks are needed any more.
In case of problems contact  me (x7224, Jose.Hernandez@desy.de)
Last modified: Mon Dec 10 21:50:26 MET 2001