I am generating a bunch of tiles for a rendering of the data imported from
LINZ/NZOGPS (pre-merge).
There are obviously quite a few sea & land tiles, and my virtual machine is
likely to run out of space. I got thinking about this, and realised the land
(grey) tiles could be hardlinked to a single grey image, and the sea (blue)
tiles could be hardlinked to a single blue image.
The blank tiles are all 256 bytes, but I assume they will use up a disk block
(I think 4k). There are more than half a million of these, and at 4k, this
makes about 2GB (and counting), ie 76% of the overall tileset is rubbish.
I did an md5sum on them, and for some reason the grey (land) ones all have the
same checksum:
e.g. 91591e38499af234ff1e55b634329fed 13/7906/5276.png
The blue ones, however, don't seem to have this property for whatever reason:
md5sum 13/7906/5279.png
80d8ddebacbc0a7a16ef799f4b9763d7 13/7906/5279.png
md5sum 13/7906/5280.png
edede53ee6ba4e06efa8ae2bdb3965a4 13/7906/5280.png
md5sum 13/7906/5281.png
3fe002719775913621f3ef23f0d2589b 13/7906/5281.png
Anyway, has anyone got any recipes for hardlinking these? I'm not sure why the
blue tiles have different content (even if they are all rendered blue), any
ideas?
_______________________________________________
dev mailing list
[email protected]
http://lists.openstreetmap.org/listinfo/dev
