[gdal-dev] vrt and too many open files error

[Julien Michel]

Thanks Even, it worked.

Regards,

Julien

Le 06/10/2017 à 17:55, Even Rouault a écrit :
>
> On vendredi 6 octobre 2017 17:29:40 CEST Julien Michel wrote:
>
> > Dear all,
>
> >
>
> > I have a VRT file, which I generated by a script I wrote, that simply
>
> > mosaics 2750 tiles (images of the same size). I can not read back this
>
> > vrt file with gdal, it says:
>
> >
>
> > $ gdalinfo cloud_plain.vrt
>
> >
>
> > ERROR 4: Too many open files
>
> > gdalinfo failed - unable to open 'cloud_plain.vrt'.
>
> >
>
> > Reading this tracker [1], I think it should not complain ? Note that
>
> > this happens when parsing the vrt file, not actually reading data. If I
>
> > gdal_translate only a small portion spanning a few tiles, it will still
>
> > complain. Shall I file a bug report or is this behavior expected ?
>
> Julien,
>
> it is likely that if you built it at hand that your VRT sources lack a 
> SourceProperties element
>
> <SourceProperties RasterXSize="xxx" RasterYSize="xxx" DataType="xxx" 
> BlockXSize="xxx" BlockYSize="xxx" />
>
> Without that element, GDAL must open each file, and you hit the 1024 
> file descriptor limit
>
> ~~~
>
> That said, in theory the VRT driver could be improved to avoid having 
> that element at all (and it would be desirable not having it). It is 
> just needed so we can instanciate a ProxyDataset object since it needs 
> to know those characteristics, but the VRT logic itself shouldn't need 
> them until it identifies that it must read from the source. At the 
> time where I improved that point in GDAL, I was still a bit unfamiliar 
> with the code base and didn't dare touching that aspect ;-)
>
> Even
>
> -- 
>
> Spatialys - Geospatial professional services
>
> http://www.spatialys.com
>

-- 
Julien MICHEL
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