[linux-lvm] lvm_lv_deactivate seems to have no effect, LV is still available in lvdisplay

[Alexander Lyakas]

Hello everybody,
I am using stock ubuntu natty with lvmlib 2.02.66:
root at 11:/mnt/work/alex# uname -a
Linux 11 2.6.38-8-server #42-Ubuntu SMP Mon Apr 11 03:49:04 UTC 2011
x86_64 x86_64 x86_64 GNU/Linux

In my code I open a VG, iterate over all the LVs and then call
lvm_lv_deactivate() on each LV. The return value is 0, and also
immediately after that, I call lvm_lv_is_active() for each LV and
assert that it returns 0 (not-active).
Later in the code, I close the VG handle.

However, when I issue lvdisplay from command-line, I still see:
LV Status              available
and the dm device files for the LVs are also present (/dev/dm-0 etc).

As a result I cannot later stop the underlying md devices (PVs) using
'mdadm --stop'.
If I do lvchange -an from the command line later, it succeeds, LV
status becomes 'NOT available' and I am able to stop the md arrays.

>From looking at the code of lvmlib, it looks like lvm_lv_deactivate()
does not require lvm_vg_write(); I see that lvchange implementation
does not seem to call this when de-activating LVs. Still, I have tried
to call lvm_vg_write() with same effect.

No other application on the machine uses the same VG (at least not
that I know of).

Can anybody please advise what I might be missing.

Thanks,
  Alex.