Re: `boot-floppies' <current> directory structure spec.
On Tue, 7 Mar 2000, Karl M. Hegbloom wrote:
> Use `ls -lRi' to make it list inode numbers. When I did it, on the
> isofs, the "links" have different inodes. They are *not* hard links,
> they are copies.
Inode numbers are absolutely untrustworthy for CDs. Inodes _don't_exist_ on
CDs, so the kernel just makes them up. It's amazing that they even stay the
same for each ls -lRi...
On an iso9660 fs, files are stored linearly - no fragmentation is possible,
there are no "file allocation tables" etc. A file is found by 1) its starting
block (1 block = 2048 bytes) and 2) its length. Both these things are stored
in the directory entry of each file.
The `isoinfo' program I mentioned shows the actual (and real!) sector on which
the file begins. Given that starting block and length are the same (verified
at the binary level!), those files share the same disk space. This is true for
all OSes, because there's no OS that checks if multiple files refer to the
same place on the CD and then report an error.
I could probably show you this with the official iso9660 specs and some
example CDs, but I'd rather not have to...