lvl=warn msg="Couldn't find the CGroup pids controller, process limits will be ignored." t=2017-07-26T10:11:35+0900
lvl=info msg="Kernel uid/gid map:" t=2017-07-26T10:11:35+0900
lvl=info msg=" - u 0 0 0" t=2017-07-26T10:11:35+0900
lvl=info msg=" - g 0 0 0" t=2017-07-26T10:11:35+0900
lvl=info msg="Configured LXD uid/gid map:" t=2017-07-26T10:11:35+0900
lvl=info msg=" - u 0 100000 65536 (unusable)" t=2017-07-26T10:11:35+0900
lvl=info msg=" - g 0 100000 65536 (unusable)" t=2017-07-26T10:11:35+0900
lvl=warn msg="One or more uid/gid map entry isn't usable (typically due to nesting)" t=2017-07-26T10:11:35+0900
lvl=warn msg="Only privileged containers will be able to run" t=2017-07-26T10:11:35+0900
lvl=info msg="Connecting to a remote simplestreams server" t=2017-07-26T10:11:35+0900

error: Error calling 'lxd forkstart artful /var/lib/lxd/containers /var/log/lxd/artful/lxc.conf': err='Failed to run: /usr/bin/lxd forkstart artful /var/lib/lxd/containers /var/log/lxd/artful/lxc.conf: '
  lxc 20170726020609.465 ERROR lxc_cgfs - cgroups/cgfs.c:lxc_cgroupfs_create:901 - Could not find writable mount point for cgroup hierarchy 4 while trying to create cgroup.
  lxc 20170726020609.465 ERROR lxc_cgfs - cgroups/cgfs.c:cgroup_rmdir:209 - Device or resource busy - cgroup_rmdir: failed to delete /sys/fs/cgroup/systemd//system.slice/lxd.service