subgid (5)

Each line in /etc/subgid contains a user name and a range of subordinate group ids that user is allowed to use. This is specified with three fields delimited by colons (“:”). These fields are:

login name

numerical subordinate group ID

numerical subordinate group ID count

This file specifies the group IDs that ordinary users can use, with the newgidmap command, to configure gid mapping in a user namespace.

Multiple ranges may be specified per user.

/etc/subgid

Per user subordinate group IDs.

/etc/subgid-

Backup file for /etc/subgid.

login.defs(5), newgidmap(1), newuidmap(1), newusers(8), subuid(5), useradd(8), userdel(8), usermod(8), user_namespaces(7).