OpenVZ to LXC Migrations Issue - Cointainer Does not Start

[Michal Unzeitig]

Migrating from Proxmox 3.1 to 5.1.
Successfully migrated couple of Ubuntu containers already.
Now stuck with Centos (6.x) container - migration went ok, but after container start, no access via console or network.

Using debug, looks like it hangs at:

lxc-start 102 20171029185125.850 NOTICE   lxc_conf - conf.c:lxc_setup:3272 - Container "102" is set up
lxc-start 102 20171029185125.851 INFO     lxc_apparmor - lsm/apparmor.c:apparmor_process_label_set:238 - changed apparmor profile to lxc-container-default-cgns
lxc-start 102 20171029185125.853 NOTICE   lxc_start - start.c:start:1552 - Exec'ing "/sbin/init".
lxc-start 102 20171029185125.888 NOTICE   lxc_start - start.c:post_start:1563 - Started "/sbin/init" with pid "28043".
lxc-start 102 20171029185125.888 NOTICE   lxc_start - start.c:signal_handler:341 - Received SIGCHLD from pid 27973 instead of container init 28043.
lxc-start 102 20171029185125.888 DEBUG    lxc_commands - commands.c:lxc_cmd_handler:1037 - Peer has disconnected for "get_init_pid"
lxc-start 102 20171029185125.888 DEBUG    lxc_commands - commands.c:lxc_cmd_handler:1037 - Peer has disconnected for "get_cgroup"
lxc-start 102 20171029185125.888 DEBUG    lxc_commands - commands.c:lxc_cmd_handler:1037 - Peer has disconnected for "get_state"
lxc-start 102 20171029185125.889 DEBUG    lxc_commands - commands.c:lxc_cmd_handler:1037 - Peer has disconnected for "get_cgroup"
lxc-start 102 20171029185125.889 DEBUG    lxc_commands - commands.c:lxc_cmd_handler:1037 - Peer has disconnected for "get_state"
lxc-start 102 20171029185125.889 DEBUG    lxc_commands - commands.c:lxc_cmd_handler:1037 - Peer has disconnected for "get_init_pid"
lxc-start 102 20171029185128.127 DEBUG    lxc_commands - commands.c:lxc_cmd_handler:1037 - Peer has disconnected for "get_init_pid"
lxc-start 102 20171029185128.129 DEBUG    lxc_commands - commands.c:lxc_cmd_handler:1037 - Peer has disconnected for "get_cgroup"
...

The DEBUG lines are then repeating over and over until I shutdown the container manually. Container CPU running at 100%.

Any ideas, what may be wrong here?