$ pct list
VMID       Status     Lock         Name
200        running                 proxy
201        running                 adguard
202        running                 wireguard
203        running                 unifi

$ pct start 200
 
$ pct stop 200

$ lvdisplay | grep "LV Path\|LV Size"
 
LV Path                /dev/pve/swap
  LV Size                <7.70 GiB
  LV Path                /dev/pve/root
  LV Size                69.57 GiB
  LV Size                <141.81 GiB
  LV Path                /dev/pve/vm-200-disk-0
  LV Size                8.00 GiB
  LV Path                /dev/pve/vm-201-disk-0
  LV Size                16.00 GiB
  LV Path                /dev/pve/vm-202-disk-0
  LV Size                10.00 GiB
  LV Path                /dev/pve/vm-203-disk-0
  LV Size                15.00 GiB

$ e2fsck -fy /dev/pve/vm-200-disk-0
 
e2fsck 1.46.5 (30-Dec-2021)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/pve/vm-200-disk-0: 36575/524288 files (0.1% non-contiguous), 315796/2097152 blocks

$ resize2fs /dev/pve/vm-200-disk-0 4G
 
resize2fs 1.46.5 (30-Dec-2021)
Resizing the filesystem on /dev/pve/vm-200-disk-0 to 1048576 (4k) blocks.
The filesystem on /dev/pve/vm-200-disk-0 is now 1048576 (4k) blocks long.

$ lvreduce -L 4G /dev/pve/vm-200-disk-0
 
  WARNING: Reducing active logical volume to 4.00 GiB.
  THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce pve/vm-200-disk-0? [y/n]: y
  Size of logical volume pve/vm-200-disk-0 changed from 8.00 GiB (2048 extents) to 4.00 GiB (1024 extents).
  Logical volume pve/vm-200-disk-0 successfully resized.
 
  /!\ note:
  edit also the "rootfs" entry in /etc/pve/lxc/200.conf

$ qm list
      VMID NAME                 STATUS     MEM(MB)    BOOTDISK(GB) PID
       900 cryptowallets        stopped    8192              50.00 0