On Mon, 2009-01-19 at 14:54 +0100, Helge Hafting wrote: > Carlo Minucci wrote: > > http://wiki.openmoko.org/wiki/Yaouh! > > > > i a simple interface for update the maps of tangogps > > it's optimized for low band usage > > A very good idea, but it does not work yet. > > My maps are in /media/card/kart/, > but yaouh thinks they are in /home/root/Maps. > so it doesn't check my 50000 tiles. > > I have tangogps set up that way, because there is > more room on the 8GB card, and it isn't blanked when I flash > a new SHR image. > > I do not know where tangogps keeps this information though. > > Helge Hafting >
After trying a few different things, now one of my first moves is to delete /home/root/Maps and replace it with a symlink to the SD card Maps directory. Rather than use the yaouh script, the first version of which didnt like the symlink, I used the idea (thanks for putting me onto E-TAG) in a quick perl lashup - works fine (well, working fine as I have ~840000 png files totalling 3.3Gb and its been running since soon after yaouh was announced - will be awhile yet!) I use a master archive on my desktop for this - and syn the freerunner to this using rsync. Some things I ran into with such a large number of maps: ext2/3 is not really suited to storing such a large number of small files. The main problem is the fixed number of inodes which I ran out of despite having 2Gb still free on the SD card partition :( To work around, create the file system with "-b 1024 -i 1024" for the maximum number of inodes - unfortunately this cant be changed after the FS is created. Where I live (Perth, Western Australia) there are large areas of surrounding sea/land/forestry/desert etc that use a single colour tile - each of only 103 bytes. I symlinked all identical files (based on md5sum) such that only one copy of each is kept. This has the advantage that as ext2/3 uses fast-symlinks, the actual symlink (provided the path is < 60 characters) is stored in the inode and doesnt take any block space on the FS. This shrinks the size as given by du -sh from 3.3Gb down to ~550Mb. Pity ext2/3 doesnt do tail packing, but maybe reiserfs which would be a lot more suitable will come into the FR one day. When I get time, I hope to investigate a loopback like tarfs or squashfs to see if that can improve this wasted space. I'll need to finish my current update and create a new symlinked archive to see how much wastage tail packing would save - should be a fair bit. Lastly, I would get occasional lockups, blank tiles and FS corruption from tango - eventually traced it to the SD card clock - if you see this look up "sdclk" on the wiki and slow it down a bit. Have fun, BillK _______________________________________________ Openmoko community mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/community
