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.
This page is part of the shadow-utils (utilities for managing
accounts and shadow password files) project. Information about the
project can be found at ⟨http://pkg-shadow.alioth.debian.org/⟩. If
you have a bug report for this manual page, see
⟨http://pkg-shadow.alioth.debian.org/getinvolved.php⟩. This page was
obtained from the project's upstream Git repository
⟨git://anonscm.debian.org/git/pkg-shadow/shadow.git⟩ on 2017-03-13.
If you discover any rendering problems in this HTML version of the
page, or you believe there is a better or more up-to-date source for
the page, or you have corrections or improvements to the information
in this COLOPHON (which is not part of the original manual page),
send a mail to email@example.com
shadow-utils 4.4 02/18/2017 SUBGID(5)