Hi guys, I am the developer of the gdal_retile. Using gdal_retile on very large images only makes sense if you plan to import your tiles into a jdbc database. Serving images from so many files is not recommended.

I tested on an AIX Box, tiling an 80 GB Erdas image. The performance decrease was due to the increasing number of files in the file system. I had about 1 million of individual files. Deleting or moving this file set was a reason for drinking a cup of coffee. (15 - 30 minutes). And we are talking here from an AIX Box having a JFS file system and fast server disks.

Please check this symptom in your environment, look for the number of files you have created and the performance.

I am interested if this symptom occurs on your platforms too.

Cheers
Christian


Quoting Elijah Robison <eli...@villagis.com>:

Hi Nikos,

I also have difficulty tiling large, high res images with gdal_retile.
I would say our average process--a county-wide, 1-foot resolution
ECW--takes about a month to run to completion.

At first, tiles are generated with blazing speed.  But by the time the
routine has been running for about 24-hours, it slows to a crawl.  Is
this the symptoms you are experiencing or are you running into
something else?

I would very much love to get to the bottom of this and find a way to
maintain the original performance throughout a tiling routine.

Best, Elijah Robison


nickos85 wrote:
Hi,

I have a mapserver and a high resolution image about 4GB when i make the
image tiles with a size of 512x512 using gdal_retile I have better result
instead of a tile size of 256x256. I think the problem is on how the search
algorithm for the location of the tile can be improoved. Any suggestions?

--Nikos Hatzopoulos
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