the rule of thumb is 32KBs for small, many files and 64KBs for large files. I'm not sure if that will work or what issue you're having as I've never tried a linux emulator on the 360. maybe I mentioned this, but you might try loading xell through the xell launcher (found with dashlaunch). I'm not sure if that would have any effect, but there are mods of xell that that is perfect for. 
