]> newuidmap 1 User Commands shadow-utils &SHADOW_UTILS_VERSION; newuidmap set the uid mapping of a user namespace newuidmap pid uid loweruid count uid loweruid count ... The newuidmap sets /proc/[pid]/uid_map based on it's command line arguments and the uids allowed in /etc/subuid. There currently are no options to the newuidmap command. /etc/subuid List of users subordinate user IDs. /proc/[pid]/uid_map Mapping of uids from one between user namespaces. login.defs5 , newusers8 , subuid5 , useradd8 , usermod8 , userdel8 .