Re: flummoxed why I can't umount my md device. fuser and lsof show no files locked

[Phil Turmel <philip@turmel.org>]

Hi Simon,

On 06/20/2011 02:16 PM, Simon McNair wrote:
> Hi Roman,
> Sorry for the stupid omission, I did try running umount /media/local/Raid to no avail.  The other thing I also tried was the lazy dismount option, but it never unmounted, I did a force, then remount and dismount, but it didn't make any difference to the errors.  none of the processes have a working directory in the Raid folder as it is just for storage, the OS and apps are on a separate drive entirely.  I also ensured that my ssh session was not in the /media/local folder either.
> 
> I am pretty sure that I actually want the array running in order to run a mkfs against it (obviously) I just tried that as a last ditch attempt.  I'm really just trying to figure out how I can find out what process has the folder locked if lsof and fuser can't tell me :-)

You have to consider that the kernel itself may be holding it open.  The most common cause in my experience is a loop mounted file, or stacked userspace filesystem.  What does lsdrv[1] say?  If a loop device is active, run "losetup -a".

Phil

[1] http://github.com/pturmel/lsdrv