Reduce Proxmox Root LV
boot into gparted (make bootable usb https://gparted.org/liveusb.php)
run lvdisplay to check the proxmox root and data lv name and path
sudo lvdisplay
should find something similar to:
--- Logical volume ---
LV Path /dev/pve/root
LV Name root
VG Name pve
LV UUID A4ffmM-vOx2-vGUJ-xOs8-Xjzv-klDq-zRrEHz
LV Write Access read/write
LV Creation host, time proxmox, 2021-11-03 14:37:35 +0000
LV Status available
# open 1
LV Size 25.00 GiB
Current LE 6400
Segments 1
Allocation inherit Read ahead sectors auto - currently set to 256
Block device 253:3
--- Logical volume ---
LV Name data
VG Name pve
LV UUID 16uDfQ-2lIf-jB8H-XIBc-X4y5-MuRj-QvwAQr
LV Write Access read/write(activated read only)
LV Creation host, time proxmox, 2021-11-03 14:37:36 +0000
LV Pool metadata data_tmeta
LV Pool data data_tdata
LV Status available
# open 0
LV Size \<425.72 GiB
Allocated pool data 64.65%
Allocated metadata 4.32%
Current LE 108984
Segments 1
Allocation inherit Read ahead sectors auto - currently set to 256
Block device 253:14
resize the root lv (choose size... 25G is probably good)
sudo lvreduce --resizefs -L {size}G /dev/pve/root
resize the data lv to use all available space
sudo lvresize -l +100%FREE /dev/pve/data