Hi
Atm. the load on cassini is around 20 and the diff imports are fighting
to stay up. I think it's cmarq's hillshade-generator takes the most
resources on cassini. top reports ~57.1% IO waiting so I think there's a
lot of disk going on.
I tried to do a "du -hs /mnt/user-store/osm_hillshading" but ir ran
loooong until I canceled it.
What I think is going on is that the generate_tiles script creates a
real huge number of single pngs. Unlike mod_tile it is not combining the
small tiles into larger chunks (mod_tile packs 8x8 tiles into a
metatile). Also unless mod_tile it renders each and every tile in each
and every zoomlevel, while mod_tile only renders tiles that are really
shown (e.g. it leaves out most of the atlantic at zoomlevel 18, as
nobody would view the empty sea at this zoomlevel.
Both problems together create a real huge number of files in a single
directory which is not good for most filesystems. To make things worse,
/mnt/user-store is connected to cassini via NFS, so there's another
bottleneck.
I don't know it this really is a problem, but I think it's worth talking
about it.
Peter
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