[GRASS-dev] [GRASS GIS] #2764: corrupt data written to FCELL and DCELL rasters, hard to re-produce

GRASS GIS trac at osgeo.org
Sun Jan 7 23:59:58 PST 2018

#2764: corrupt data written to FCELL and DCELL rasters, hard to re-produce
  Reporter:  dylan   |      Owner:  grass-dev@…
      Type:  defect  |     Status:  new
  Priority:  normal  |  Milestone:  7.2.3
 Component:  Raster  |    Version:  unspecified
Resolution:          |   Keywords:
       CPU:  x86-64  |   Platform:  Linux

Comment (by mmetz):

 Replying to [comment:23 dylan]:
 > As of 2017-12-30, I was again encountering the hard-to-reproduce "ERROR:
 Error reading raster data for row 1949 of <map>" errors. Just as with last
 time in the context of parallel execution. I posted [http://osgeo-
 uncompressing-raster-data-td5348054.html this message] to GRASS-user and
 then proceeded to document progress as of comment 8 in this ticket.
 > I am attaching two scripts to illustrate the latest instance, `beam-rad-
 at-tile.sh` and `daily-rad.sh`, invoked like this:
 > {{{
 > # ...
 > ## try ZLIB compression:
 > # random errors as described in #2764
 > ## try LZ4 compression:
 > # no errors!
 > #
 > # ... looping code
 > #
 > bash beam-rad-at-tile.sh $tile_i
 > # ...
 > }}}
 > Essentially, I am iterating over 5000x5000 {elevation, slope, aspect}

 The script make-hz-maps.sh called by beam-rad-at-tile.sh is missing. Is
 the exact looping code needed in order to reproduce, or does it also
 happen with any given tile?

 > computing horizon angle maps in parallel, computing daily beam radiance
 maps in parallel, summing daily maps, and then proceeding to the next
 tile. With ZLIB compression, I am randomly encountering raster read errors
 generated by `r.horizon`, `r.sun`, or `r.mapcalc` in this context. This
 seems to happen with or without NULL cells in the active tile. Errors are
 not encountered when using LZ4 compression.
 > The system is an 8-core Intel i7 950 @ 3.07Ghz with GRASS
 database/mapset residing on an SSD.
 > I'll post one of the {elevation, slope, aspect} tiles if anyone is
 interested in tinkering with them.

 Test data, or a script to generate test data would help.

Ticket URL: <https://trac.osgeo.org/grass/ticket/2764#comment:24>
GRASS GIS <https://grass.osgeo.org>

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