Stuck setting up my first container

Hi all, lxc newbie here…

I am stuck setting up my lxc environment, and can’t sort out whatever I should do to correct what is not working, I need help!

First of all, I’m on Linux Mint 18.1 32 bit.

I started reading and folowing the “Getting started” page, installed lxc, created the default.conf, created a test container by downloading a template (ubuntu > xenial > i386 iirc).

Had to install lxc-templates package first… because iirc it said there were no templates…
I found some advice in this post http://www.polarsparc.com/xhtml/LXC.html

and I was able to advance and finally get to the point where I shoud start my container…

Then I couldn’t start it.

issuing

$ lxc-start -n test -d -o log

I get

lxc-start: tools/lxc_start.c: main: 366 The container failed to start.
lxc-start: tools/lxc_start.c: main: 368 To get more details, run the container in foreground mode.
lxc-start: tools/lxc_start.c: main: 370 Additional information can be obtained by setting the --logfile and --logpriority options.

and the log file starts with

lxc-start 20180316140346.451 ERROR lxc_utils - utils.c:mkdir_p:254 - Permission denied - failed to create directory ‘/sys/fs/cgroup/blkio/lxc’

and goes down to a long list…

I issued

$lxc-checkconfig

which outputs:

Kernel configuration not found at /proc/config.gz; searching…
Kernel configuration found at /boot/config-4.4.0-75-generic
— Namespaces —
Namespaces: enabled
Utsname namespace: enabled
Ipc namespace: enabled
Pid namespace: enabled
User namespace: enabled
Warning: newuidmap is not setuid-root
Warning: newgidmap is not setuid-root
Network namespace: enabled
Multiple /dev/pts instances: enabled

— Control groups —
Cgroup: enabled
Cgroup clone_children flag: enabled
Cgroup device: enabled
Cgroup sched: enabled
Cgroup cpu account: enabled
Cgroup memory controller: enabled
Cgroup cpuset: enabled

— Misc —
Veth pair device: enabled
Macvlan: enabled
Vlan: enabled
Bridges: enabled
Advanced netfilter: enabled
CONFIG_NF_NAT_IPV4: enabled
CONFIG_NF_NAT_IPV6: enabled
CONFIG_IP_NF_TARGET_MASQUERADE: enabled
CONFIG_IP6_NF_TARGET_MASQUERADE: enabled
CONFIG_NETFILTER_XT_TARGET_CHECKSUM: enabled
FUSE (for use with lxcfs): enabled

— Checkpoint/Restore —
checkpoint restore: enabled
CONFIG_FHANDLE: enabled
CONFIG_EVENTFD: enabled
CONFIG_EPOLL: enabled
CONFIG_UNIX_DIAG: enabled
CONFIG_INET_DIAG: enabled
CONFIG_PACKET_DIAG: enabled
CONFIG_NETLINK_DIAG: enabled
File capabilities: enabled

Note : Before booting a new kernel, you can check its configuration
usage : CONFIG=/path/to/config /usr/bin/lxc-checkconfig

so, I checked about those

Warning: newuidmap is not setuid-root
Warning: newgidmap is not setuid-root

lines, and found that I could have some mismatched permissions on newgidmap and newuidmap files, and someone suggested to do a chmod u+s or chmod +s, but can’t sort out what is wrong, how to correct it: here you find what I had and still have now, there:

$ ls -l /usr/bin/new*map
-rwsr-xr-x 1 root root 36288 mag 17 2017 /usr/bin/newgidmap
-rwsr-xr-x 1 root root 36288 mag 17 2017 /usr/bin/newuidmap

I struggled to find a rally similar situation on search engines and such, but either I don’t understand, or my issue is somewhat different from all I found…

Can anyone help me with this issue?

Thanks, Marco