Finally I can move back to proxmox from solusvm LXC was hell without loadavg not working but finally it is.I tested and it seems to work as expected! At least in w, htop and nagios nrpe check_load it reports proper values. Thats great!
Now i wonder if there's proper way for the -l parameter to survive upgrade of lxcfs package...
update: it can be done using systemd overrides:
execute systemctl edit lxcfs
type following and save the file:
ExecStart=/usr/bin/lxcfs -l /var/lib/lxcfs/
this will get automaticaly saved to /etc/systemd/system/lxcfs.service.d/override.conf file
note that the ExecStart= line deletes original definition, otherwise there would be two ExecStart statements after override is applied
to revert to default execute systemctl revert lxcfs