subuid(5) - phpMan

SUBUID(5)                File Formats and Conversions                SUBUID(5)

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:
       o   login name or UID
       o   numerical subordinate user ID
       o   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.
       When large number of entries (10000-100000 or more) are defined in
       /etc/subuid, parsing performance penalty will become noticeable. In
       this case it is recommended to use UIDs instead of login names.
       Benchmarks have shown speed-ups up to 20x.
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 4.6                  08/09/2019                         SUBUID(5)