[CentOS] can NOT delete LV (in use) problem...

We have CENTOS 5.6 on DELL server.  I create VG and LV on one SSD disk.  after couple weeks I decide to delete it.

I unmount file system but can not delete LV.  It say "in use".
I try following but still NOT work:


# lvchange -an /dev/VG0-SSD910/LV01-SSD910
  LV VG0-SSD910/LV01-SSD910 in use: not deactivating
# kpartx -d /dev/VG0-SSD910/LV01-SSD910
# lvchange -an /dev/VG0-SSD910/LV01-SSD910
  LV VG0-SSD910/LV01-SSD910 in use: not deactivating

Anyone have ideal how to delete it?

Thanks.