# phpman > man > subgid(5)

[SUBGID(5)](https://www.chedong.com/phpMan.php/man/SUBGID/5/markdown)                           File Formats and Conversions                           [SUBGID(5)](https://www.chedong.com/phpMan.php/man/SUBGID/5/markdown)



## 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)](https://www.chedong.com/phpMan.php/man/login.defs/5/markdown), [**newgidmap**(1)](https://www.chedong.com/phpMan.php/man/newgidmap/1/markdown), [**newuidmap**(1)](https://www.chedong.com/phpMan.php/man/newuidmap/1/markdown), [**newusers**(8)](https://www.chedong.com/phpMan.php/man/newusers/8/markdown), [**subuid**(5)](https://www.chedong.com/phpMan.php/man/subuid/5/markdown), [**useradd**(8)](https://www.chedong.com/phpMan.php/man/useradd/8/markdown), [**userdel**(8)](https://www.chedong.com/phpMan.php/man/userdel/8/markdown),
       [**usermod**(8)](https://www.chedong.com/phpMan.php/man/usermod/8/markdown), **user**___**[namespaces**(7)](https://www.chedong.com/phpMan.php/man/namespaces/7/markdown).



shadow-utils 4.8.1                           02/06/2024                                    [SUBGID(5)](https://www.chedong.com/phpMan.php/man/SUBGID/5/markdown)