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Since the beginning of time (or as long as I remember anyway) linux systems have had a "sys" and an "adm" group. What is the canonical use for them? Would it be appropriate to use either for a "super user" group? (Group permissions on directories, in sudoers, etc).

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I suspect this one is going to be a tough one to define, w/ some of these groups likely dating back to days of Unix yore. Some Linux distros may actually use these groups. Arch, for example, actually defines their usage: – Evan Anderson Mar 7 '13 at 6:20
Might be better question for . I asked a similar question about the operator user – Stefan Lasiewski Mar 18 '13 at 15:38
up vote 8 down vote accepted

There is no standard requiring any interoperability meaning of this groups.

Traditionally the adm group is used to give a user access to some sort of system log files.
See e.g. ls -l /var/log.

The sys group normally intended to give a user some kind of administration rights. E.g. archlinux use this group for cups administration. Other distributions behave differently.
E.g. on ubuntu the group lpadmin is used for cups administration. The sys group here is still defined, but seems to be unused.

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You can list the groups by this:

$cat /etc/group

Uses of adm and sys groups:

adm: Group adm is used for system monitoring tasks. Members of this group can read many log files in /var/log, and can use xconsole. Historically, /var/log was /usr/adm (and later /var/adm), thus the name of the group.

system : This group is used for configuration and maintenance for hardware and software.

Hope this link will help..

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