The following is a response I wrote to a discussion on the German mailinglist. I post it here because perhaps it’s useful to people who want to setup their own map hosting service.
When I type in Google: “Free Garmin maps” I find my website listed first
and the OSM Garmin/Download wiki page listed in 4th place.
Similarly searching for “OpenStreetMap Garmin map” lists my website
first and the OSM Garmin/Download wiki page in 5th place.
Similar results are returned using Bing search.
So, I don’t really understand why people can’t find the maps.
Ofcourse this is a good idea. E.g. The Dutch OSM page has such a link.
The current server is a few generations old dual CPU dualcore Xeon 2.0
GHz (4 cores total), 8 GB ram, 900 GB cache and 100 Mbit internet
The server generates 3 maps simultaneously at a rate up to about 500
unique maps per 24 hours. It could be more but at this pace the cache is
usually full within 24 hours and map generation is throttled. Also the
internet connection is sometimes fully saturated which takes it’s toll
on disk performance (i.e. disk heads are moving as fast as they can
while the system is starved for data), this slows the generation of maps.
About 1500 unique users download one or more maps per day at a rate of
around 300GB per day. Caching levels are about 30% I would guess
(unfortunately I don’t have good numbers on that), it helps tremendously.
So if you plan on setting up a similar on-demand system that provides
more map types to more people then use at least:
- a modern quadcore CPU
- 2 TB fast disk cache
- Good 100 MBit internet
- 8 GB ram
- unlimited bandwidth usage
I also have experience with on-demand rendering using a renderfarm in
which case the CPU and disk cache per box is less important, but enough
ram and fast internet connection remain important. Configuring all the
details and distributing map updates is a pain in the ass though.
Ofcourse there is still room for smarter caching and reducing the
cache/CPU usage by producing maps more efficiently (i.e. less versions
of the same map), but it requires a lot of effort to improve significantly.
Regarding user feedback, I get a lot of it. Lots of thank you’s
ofcourse, but there is also a large group of internet users for which
you can’t make things simple enough and well-documented enough for them
to manage without help. Picture your typical computer-illiterate
mother-in-law who decides that she needs a free update for her satnav
using the babysitter on this side of the screen. Or freshly pensioned
guy who decides he’s going to pick up the geocaching hobby but never
used a pc before.
Those WILL contact you and expect to be helped, for free.
So, if you plan on setting up a similar system like I did: plan for a
lot of your time to perform helpdesk duties answering silly questions,
figuring out what the h*ll people are trying to tell you and find ways
around individual firewall/virusscanner/InternetExplorer problems, etc.
*PS. No personal insults intended *