- no hard-links
- no mknod support
- no access right checks
- no support for extended attributes and ACLs
- tested on Linux only currently
- no self-containment properties in respect to the database
- bonnie doesn't pass yet:
  /usr/sbin/bonnie++ -d mnt/ -x 1 -s 16:8192 -r 0
  Writing with putc()...done
  Writing intelligently...done
  Rewriting...Can't read a full block, only got 0 bytes.
  Bad seek offset
  Error in seek(0)