OK, so you’ve made a cloned LXC snapshot container with:

lxc-clone -o template -n TEMPLATE_NEW_TEST -s -v LVM_VOL

And you like the changes, want to commit them to the original container? Here’s the solution

lvconvert –merge /dev/LVM_VOL/TEMPLATE_NEW_TEST

or, you just delete it with

lvremove /dev/LVM_VOL/TEMPLATE_NEW_TEST

Make sure to remove the container folder too.

Source: http://serverfault.com/questions/184983/how-to-keep-or-drop-lvm-snapshot