Provided by: passwd_4.2-3.1ubuntu5.4_amd64 

NAME
subgid - the subordinate gid file
DESCRIPTION
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.
FILES
/etc/subgid
Per user subordinate group IDs.
/etc/subgid-
Backup file for /etc/subgid.
SEE ALSO
login.defs(5), newgidmap(1), newuidmap(1), newusers(8), subuid(5), useradd(8), userdel(8), usermod(8),
user_namespaces(7).
shadow-utils 4.2 03/26/2019 SUBGID(5)