The magic of ReiserFS

Michael michael at
Mon Nov 23 19:51:22 CET 2009

I bought an 8GB micro sd card with the intention of storing  
OpenStreetMap tile for Tango GPS onto it. I could store up to zoom  
level 14, but zoom level 15 was one step too far in terms of size. I  
knew this was due to the block size of the filesystem, but even a  
block size of 512 bytes would have a lot of overhead. I had read about  
the small file performance of reiserfs, so I thought I would give it a  
try. I created a sparse file reiserfs filesystem and loopback mounted  
it and copied the files up to zoom level 15 onto it. Amazingly the  
sparse file only grew to 2.6GB while the tar file for zoom level 14  
alone was 2.5GB. I copied the sparse file onto the micro sd, inserted  
it into the Neo, and booted it with a reiserfs enabled kernel. The  
file mounted on the Neo ok and Tango GPS seemed to be able to read the  
files ok (made sure it could do it with the internet disconnected).
I ran a du on the Maps directory and it came to 9.7GB, but reiserfs  
managed to get the storage down to 2.6GB which certainly seems like  
magic, especially since it also managed to outdo tar as well. I am  
going to see if I can get zoom level 16 onto the card as well.

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