Re: Problem with umount/umount2

[lorian@fsavigny.de]

Sebastian,

  > >  I have mounted /dev/hde6 as /usr, /dev/hde5 as /home and
  > >  /dev/hde8 as /var. When I shutdown there is always a message
  > >  from umount2 that /usr was busy etc, and when I reboot next
  > >  time it always does the checking of /dev/hde6. The other drives
  > >  appear to be unmounted cleanly.

Postponing the question about what is umount2, have you considered
what the manpage says:

       Note that a file system cannot be  unmounted  when  it  is
       `busy'  - for example, when there are open files on it, or
       when some process has its working directory there, or when
       a  swap file on it is in use.  The offending process could
       even be umount itself - it opens libc,  and  libc  in  its
       turn  may  open  for example locale files.  A lazy unmount
       avoids this problem.

I don't suppose this is already the answer, but have you tried 'strace
umount'? On my system, this reveals umount does in fact open a few
files in /usr (libc6 itself, though, is in /lib). I was interested in
this question because I have /usr/lib on a separate partition, which
initially caused problems during init, when programs couldn't make
their library calls.

  > >  I run unstable on another machine with 2.4.8, but I do not have
  > >  this same trouble; man umount does not refer to umount 2. On
  > >  the Knoppix one, man umount does refer to umount2.

Maybe this is too naive and blunt an explanation, but there is a
manpage in section 2 (system calls) called umount. Program (section 8,
system administration) and system call have the same name. Are you
in fact talking about umount(2)?

Or is there really a program named umount2? And why is it needed?

Curious, 

Florian