Docker configuration with direct-lvm in a machine with single disk

Hi I want install docker with direct-lvm
in manual they write :
“storage-driver”: “devicemapper”,
“storage-opts”: [

In my machine i have disk /dev/sda with 2 partitions

Device Free Used Total Pool Mount point

/dev/sda 1.17 TB PARTITIONED
/dev/sda1 200.00 MB /boot
/dev/sda2 0.00 KB 1.17 TB 1.17 TB vg

LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root vg -wi-ao---- 1,17t

The parttion /dev/sda2 it is installed also my OS. How to install? Can i use /dev/sda2 for creatinng a second VG docker inside the same partition and LV thinpool and thinpoolmeta or i have forcely to create another physical partition?