Re: pivot_root. unmount old root

[Stephen Powell <zlinuxman@wowway.com>]

On Tue, 23 Mar 2010 05:18:03 -0400 (EDT), K. Haselhorst wrote:
> Stephen Powell wrote:
>> But where exactly is the failure occuring?
>> Does the mount command fail?
>> Does the pivot_root command fail?  Does exec chroot fail?
> 
> The umount command fails with "device is busy". privot root and chroot
> work fine.

So everything works except the umount.  Interesting.  From the example
in the man page they obviously expect it to be possible to umount the
old root file system.

>> Kill should be able to kill any process *except* init itself.
>> And "telinit -u" should be able to refresh init.
> 
> I did a telinit u after the chroot and killed the remaining processes.
> After that lsof doesn't show any open files under old-root but umount
> still fails with "device is busy".

Maybe lsof doesn't necessarily list everything.  What does "fuser -m /old_root"
show?  What about doing "fuser -k -m /old_root"?

-- 
  .''`.     Stephen Powell    <zlinuxman@wowway.com>
 : :'  :
 `. `'`
   `-