Linux – the difference between the system group and netgroup
linux
What is the difference between the system group and netgroup (at least on ubuntu)?
Best Answer
"System groups" (often just "groups") contain users[1], and are one of the basic security concepts in UNIX and many other operating systems. Each user belongs to a primary group and any number of secondary groups; a group, like a user, can be allowed to access or modify certain files and directories using the usual chown, chmod, chgrp, setfacl tools.
"Netgroups", on the other hand, are part of NIS/YP directory services system used only in Unix-like systems. A netgroup contains entries in the form (hostname, user, nis-domain) (with all three items optional), and can describe a user on any host, any user on a specific host, and such. Netgroups are not used with files directly, but only by NIS-aware programs: NFS exported filesystems, sudo, system login rights.
[1] Other operating systems may allow more advanced configurations; e.g. Windows NT supports groups as group members.
fsck is just the original name. When they came out with new file systems they would need a specific tool for each one, efsck for ext, e2fsck for ext2, dosfsck, fsckvfat. So they made fsck the front end that just calls whichever is the appropriate tool.
The adm group is only good for viewing all the log files in /var/log (which historically used to be called /var/adm). It has no relation to sudo or root.
Best Answer
"System groups" (often just "groups") contain users[1], and are one of the basic security concepts in UNIX and many other operating systems. Each user belongs to a primary group and any number of secondary groups; a group, like a user, can be allowed to access or modify certain files and directories using the usual
chown,chmod,chgrp,setfacltools."Netgroups", on the other hand, are part of NIS/YP directory services system used only in Unix-like systems. A netgroup contains entries in the form
(hostname, user, nis-domain)(with all three items optional), and can describe a user on any host, any user on a specific host, and such. Netgroups are not used with files directly, but only by NIS-aware programs: NFS exported filesystems, sudo, system login rights.[1] Other operating systems may allow more advanced configurations; e.g. Windows NT supports groups as group members.