On 7/14/2011 9:26 AM, Jochen Topf wrote: > Its almost certainly CPU. Try > dd if=planet-latest.osm.pbf of=copy.osm.pbf bs=1M > and you'll see how fast the files can be copied. Thats the time needed for the > disk. Everything else is CPU. > >> Does this merge time seem right/reasonable? Are there any approaches or >> tricks I am missing that can speed it up? > > Try larger buffers: > $OSMOSIS --read-xml-change $OSCFILE --read-bin > $BASEDIR/var/current-planet.osm.pbf --buffer bufferCapacity=12000 > --apply-change --buffer bufferCapacity=12000 --write-pbf $NEWPLANET > > This takes about an hour every day on a 800MHz machine. > > Jochen
Thanks everyone for the suggestions. I am using osmosis to generate a single changes.osc file already. The server is in a server farm so I don't have control over the disks. The dd command took 6 minutes 40 seconds so that proves Jochen right. With my 766MB change file the original merge command that I posted takes 106 minutes. By using Jochen's merge command with buffers and the same change file it now takes 58 minutes! I knew about the possibility of buffers but I never tried them because [1] appeared quite negative regarding them. Maybe it is out of date? Thanks, Andy [1] http://wiki.openstreetmap.org/wiki/Osmosis/Benchmarking -- Andy PGP Key ID: 0xDC1B5864 _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
