[Gdal-dev] gdal_merge.py failed for ENVI format

[Frank Warmerdam]

Nicolas Ribot wrote:
> Hi all
> (I'm glad to join the list for the first time)
> 
> I tried to merge several TIF files (representing Canada, in WGS84).
> These files represent about 6 Gb of data, so I chose the ENVI file
> type, to circumvent the 4 Gb limit of tiff files.

Nicolas,

The gdal_merge script loads the entire source image into RAM so
if your source images are large it will generally fail.  It may or
may not properly report the out of memory condition.

> I'm using FWTools-1.0.7 on Ubuntu (intel 32 bits)
> Data are on a USB disk, formatted in ext2.
> I moved the data from a fat32 partition to a NTFS one, then format the
> partition in ext2, and moved data back on this partition.
> Can this be the reason of the failure ?

I vaguely recall some odd issue with fat32 bit partitions and
large files on win32, but I don't think this will be affecting
things on linux.  I gather the output is being written to an ext2
partition?

It is likely just an out of memory condition as mentioned above.

BTW, the solution is to use gdalwarp to merge the datasets as mentioned
in another recent post here (or perhaps on fwtools mailing list?).

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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