Usando o comando lvchange / vgchange - você desativa lvm e vg.
Para ativá-lo novamente, faça o seguinte:
root@uml:~# lvchange -an /dev/vg00/lv00
root@uml:~# vgchange -an /dev/vg00
0 logical volume(s) in volume group "vg00" now active
root@uml:~# lvscan |grep vg00
inactive '/dev/vg00/lv00' [4,00 MiB] inherit
root@uml:~# vgchange -ay /dev/vg00
1 logical volume(s) in volume group "vg00" now active
root@uml:~# lvchange -ay /dev/vg00
root@uml:~# lvscan |grep vg00
ACTIVE '/dev/vg00/lv00' [4,00 MiB] inherit