To set the runtime status of the user.max_user_namespaces kernel parameter,
run the following command:
$ sudo sysctl -w user.max_user_namespaces=0
To make sure that the setting is persistent,
add the following line to a file in the directory /etc/sysctl.d:
user.max_user_namespaces = 0
When containers are deployed on the machine, the value should be set
to large non-zero value.