After loading the planet.osm file (planet-090916.osm.bz2) into an Ubuntu 9.04 virtual machine the total disk usage was 133GB after the import. The total dropped to 115GB after doing a VMWare shrink operation however it looks like to account for future near-term expansion of the OSM data I should allow for at least 200GB of storage. I’d originally hoped to store the data on a small but fast SAS 15K RAID array on my server but the current version will only barely fit so I’ll need to consider other alternatives. It looks like costs are dropping fairly fast for some of the larger 15K SAS drives so I might defer the decision for a few months as the system isn’t required for production until the start of the year. Meanwhile I’ll just slip a 1TB SATA drive into the server for testing.