phpman > man > SUBGID(5)

SUBGID(5)                           File Formats and Conversions                           SUBGID(5)



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 or UID

       •   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.

       When large number of entries (10000-100000 or more) are defined in /etc/subgid, 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/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 4.8.1                           02/06/2024                                    SUBGID(5)