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20020513: scouring McIDAS data files

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  • Subject: 20020513: scouring McIDAS data files
  • Date: Mon, 13 May 2002 00:03:18 -0600
>From: Gilbert Sebenste <address@hidden>
>Organization: NIU
>Keywords: 200205130500.g4D50Ta13471 McIDAS mcscour.sh

Gilbert,

>Weather2.admin.niu.edu's disk is full, apparent problem with McIDAS that I 
>can't figure out. Scouring isn't occurring...what does that now?

The typical way to scour McIDAS data files is to run the Bourne shell
script mcscour.sh from a cron entry.  mcscour.sh needs to be edited to
setup appropriate McIDAS environment variables and how many of each
kind of file is desired to be kept and then run from either the
'mcidas' or 'ldm' accounts;  I use the 'ldm' account.

I typically run the scouring just past 0Z with an entry like:

#
# Scour McIDAS XCD data files
#
00 21 * * * decoders/mcscour.sh

Since crontab entry times are local, not UTC, you will need to adjust
your time for your timezone.

I typically copy mcscour.sh from the ~mcidas/workdata directory
(where it gets installed with the Unidata McIDAS release) to
a directory in the PATH of the user 'ldm'.  Since the recommendation
for ldm-mcidas setup is a directory like ~ldm/decoders, I use it.

Since weather2 was working for a long time, I have to believe that
scouring McIDAS data files was working.  What changed?  Is this related
to an OS upgrade?  I wouldn't think that cron entries for any user
would be deleted in an upgrade, but I suppose that it is possible.

Another possibility is that scouring has been working, but you installed
the the addendum that allows more grib messages to be decoded by
the XCD grib decoder.  If this is the case, you will want to either
turn off grib decoding in XCD (assuming that it is turned on), or
cut down on the number of days of GRID data that you keep on disk
at any time.  Turning off grib decoding (for sites that follow my
setup recommendations) is accomplished by:

<login as 'mcidas'>
cd workdata
decinfo.k SET DMGRID INACTIVE

Adjusting the number of days of XCD-decoded GRID data kept on disk
is done in mcscour.sh:

qrtmdg.k GRID 5001 6300 1
  ^       ^    ^    ^   ^__ number of days of GRID data to keep on disk
  |       |    |    |______ last GRID file to scour
  |       |    |___________ first GRID file to scour
  |       |________________ qrtmdg.k can scour GRID or MD files
  |________________________ the McIDAS-XCD scouring routine


Tom