List Partition :

lvs -a pve

LV              VG  Attr       LSize    Pool Origin Data%  Meta%  Move Log 
data            pve twi-a-tz-- <320.10g             0.00   0.52
[data_tdata]    pve Twi-ao---- <320.10g
[data_tmeta]    pve ewi-ao----   <3.27g
[lvol0_pmspare] pve ewi-------   <3.27g
root            pve -wi-ao----   96.00g
swap            pve -wi-ao----    8.00g

Remove and create a Partition Data

lvremove pve/data
lvcreate -L 10G -ndata pve
lvconvert --type thin-pool --poolmetadatasize 10G pve/data

Extend a root

# Check free Space
vgs pve
  
lvextend -L 400G /dev/mapper/pve-root
resize2fs /dev/mapper/pve-root
df -h
lvs -a pve