Container hangs up when quit

[cybertk]

Observations:

VBoxHeadless becomes zombie process

root      3277 17.4  0.0      0     0 ?        Zl   17:34   3:18 [VBoxHeadless] <defunct>

pstree output on host

$ pstree -p -s 3277
init(1)───dockerd(1527)───docker-containe(1856)───docker-containe(2347)───bash(2363)───VBoxHeadless(3277)───{VBoxHeadl+

[cybertk]

After kill docker-container(process 2347), the process tree turns into,

$ pstree -p -s 3277
init(1)───bash(2363)───VBoxHeadless(3277)───{VBoxHeadless}(3298)

[cybertk]

bash(2363) cannot be killed by any of following signals

kill -KILL 2363
kill -INT 2363
kill -TERM 2363