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

NAME
subuid - the subordinate uid file
DESCRIPTION
Each line in /etc/subuid contains a user name and a range of subordinate user ids that user is allowed to
use. This is specified with three fields delimited by colons (“:”). These fields are:
• login name
• numerical subordinate user ID
• numerical subordinate user ID count
This file specifies the user IDs that ordinary users can use, with the newuidmap command, to configure
uid mapping in a user namespace.
Multiple ranges may be specified per user.
FILES
/etc/subuid
Per user subordinate user IDs.
/etc/subuid-
Backup file for /etc/subuid.
SEE ALSO
login.defs(5), newgidmap(1), newuidmap(1), newusers(1), subgid(5), useradd(8), userdel(8), usermod(8),
user_namespaces(7).
shadow-utils 4.2 03/26/2019 SUBUID(5)