On 01/-10/-28163 12:59 PM, Jukka Rahkonen wrote: > Frederik Ramm wrote: [...] >>> After this succeeded, I wanted to try to replicate this database, so I >>> created a pg_dump using the -Fc switch >> >> This is a bad idea because a significant amount of osm2pgsql import time >> is spent building indexes, and these are not dumped, so after restoring >> the data the same time is spent again. The only efficient way to copy an >> imported planet between two systems is to copy the raw postgresql data >> files directly, and this only works reliably if postgres, postgis and >> geos have identical versions on both systems (and of course both systems >> have the same architecture). Yes, the indexing stage typically takes about half or more of the total time. On a planet import I just did, it took 14 hours for writing of data and another 41 hours for the indexing. I have not tried how long it would take to restore a dump, but I suspect in that case not much less. > > It can be slow but it is not always a bad idea. I have a very lean Linux > virtual server with about 700 MB of memory and it is very slow to import > even Finnish excerpt with osm2pgsql. In addition import tends to fail > totally about every second time. However, the virtual box has no troubles > if I run osm2pgsql at home, upload PG dump files into server and run > restore there. Even running restore from my home computer with pgAdmin III > through a 1 Mb line upwards is faster than making import with osm2pgsql on > the Linux box. Ogr2ogr from the home PostGIS to remote PostGIS has also > worked reliably for me.
Can you describe a bit more of what your setup is, and where it fails? Which version of Postgresql, PostGis and Osm2pgsql? 32bit or 64bit? 700Mb of ram really is very low, but I would like osm2pgsql to work with little resources even if very slow. > > Finnish data may be heavy for osm2pgsql because there are rather many > polygons (407625 vs. 452944 linear features) to construct, including big > lake and land use relations. Perhaps native support for areas in OSM will > make is faster. Not sure how problematic those polygons are, but it doesn't seem to bad to me. I have just tried a Finnish import and it only took 10 minutes for the import. 5 minutes for writing of data and 5 minutes for the indexing. OK, my laptop sounds like it is more powerful than your server with 2.4GHz dual-core and 4 Gb ram, but osm2pgsql only used about 150Mb of ram. Non slim mode took overall less than 4 minutes, but that did take a little under 2 Gb of Ram, so wouldn't be feasible on your server. Kai > > -Jukka Rahkonen- > > >> Bye >> Frederik >> >> _______________________________________________ >> dev mailing list >> [email protected] >> http://lists.openstreetmap.org/listinfo/dev >> > > > > > _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
