]> newgidmap 1 User Commands shadow-utils &SHADOW_UTILS_VERSION; newgidmap set the gid mapping of a user namespace newgidmap pid gid lowergid count pid gid lowergid count ... The newgidmap sets /proc/[pid]/gid_map based on it's command line arguments and the gids allowed in /etc/subgid. There currently are no options to the newgidmap command. The only restriction placed on the login shell is that the command name must be listed in /etc/shells, unless the invoker is the superuser, and then any value may be added. An account with a restricted login shell may not change her login shell. For this reason, placing /bin/rsh in /etc/shells is discouraged since accidentally changing to a restricted shell would prevent the user from ever changing her login shell back to its original value. /etc/subgid List of users subordinate user IDs. /proc/[pid]/gid_map Mapping of gids from one between user namespaces. login.defs5 , useradd8 , usermod8 , newusers8 , userdel8 , subgid5 .