[linux-lvm] umount returns device is busy

[P. Larry Nelson]

I've been using LVM now since sometime this past summer and
everything has worked great and as advertised, until I tried
to unmount a logical volume.  And this happens on both RedHat
9 and ES_3.

I had occasion the other day to unmount one of the mounted raid 
arrays in order to upgrade some firmware.  When I tried to do an
unmount command, I got "device is busy".  Ok, I'm cd'd there
from one of my windows or something, so I make sure all open
terminal windows are *not* cd'd there.  Redo the umount command
with same result.  Weird, something's got a file open. So, I did
an lsof command and grep for the device (/dev/VG1/LV1).  Nothing.
I try greping for the mount name (/scratch/cdf).  Nothing.
It will not let me unmount the logical volume.

The system in question is running RedHat 9 w/kernel 2.4.20-24.9smp
with RedHat's lvm-1.0.3-12.  I just so happened to have built 
another system using RedHat's ES_3 w/kernel 2.4.21-4.0.1.ELsmp and
their lvm-1.0.3-15, so I thought I'd try it there.  Built an identical
logical volume, mounted it, tested it (works fine), tried to umount
the filesystem with identical results: device is busy.  Checked
again using lsof.  Nothing open on the mounted filesystem.

I went checking back thru about 4 months of this list and saw
(apparently) that no one else has this problem.  At this point
I'm a bit baffled why the umount command isn't working.  I've
also seen nothing that might address this in the LVM-HOWTO.
Then again, I could have missed it.

Ideas?

Thanks!
-- 
P. Larry Nelson (217-244-9855) | Systems/Network Administrator
461 Loomis Lab                 | U of I, CITES Departmental Services
1110 W. Green St., Urbana, IL  | Consultant to: High Energy Physics Group
MailTo:lnelson at uiuc.edu        | http://www.uiuc.edu/ph/www/lnelson
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 "Information without accountability is just noise."  - P.L. Nelson