Can’t remove logical volume

1.  lvm

2.  lvdisplay

3.  lvremove /dev/vg1/lv1

4. dmsetup info -c | grep [lv1]

 >> vg1-lv1 253 25 L--w 1 1 0 LVM-4YO6buASebpXKOmdwdzyUTZ39mfubEFG0wWxeM7gYLEisWPszglyTCA0xCAuohpF

5.  lsof | grep "major,minor"  

    > lsof | grep "253,25"

6. kill -9 [PID] (the whole pid relation)

7.  lvremove /dev/vg1/lv1 - redo Step 3