root@proxmox:/etc/pve/lxc# pct start 120
WARN: old systemd (< v232) detected, container won't run in a pure cgroupv2 environment! Please see documentation -> container -> cgroup version.
Task finished with 1 warning(s)!
root@proxmox:/etc/pve/lxc#
Editar /etc/default/grub
#GRUB_CMDLINE_LINUX_DEFAULT="quiet"
GRUB_CMDLINE_LINUX_DEFAULT="quiet systemd.unified_cgroup_hierarchy=0"
update-grub