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Old 08-06-2012, 01:56 PM   #1
NotionCommotion
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Why does root belong to any groups in a Centos 5.8 new install?


Hi,

When doing a new Centos 5.8 installation, I found that the root user was assigned to several groups (see below). My understanding is that root is all powerful and I don't understand what the point of adding root to 1(bin), 2(daemon), 3(sys), 4(adm), 6(disk), and 10(wheel) is. Any thoughts? Thanks

[root amp; localhost ~]# id
uid=0(root) gid=0(root) groups=0(root),1(bin),2(daemon),3(sys),4(adm),6(disk),10(wheel)

PS. I accidentally posted a similar message (and two others) to a non-linuxquestions.org forum, but meant to only do so at this one. I am not a "double poster" by nature, and apologize in advance.
 
Old 08-06-2012, 02:00 PM   #2
Kustom42
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This is by design to allow root access to files that require that group membership and are not owned by the root user. These can be daemon files, special character device files, etc..
 
Old 08-06-2012, 02:21 PM   #3
NotionCommotion
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Thanks Kustom42,

I thought that root has access to all files regardless of whether root owns them or root belongs to an associated group.

Is this not the case?
 
Old 08-06-2012, 03:28 PM   #4
Kustom42
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Quote:
Originally Posted by NotionCommotion View Post
Thanks Kustom42,

I thought that root has access to all files regardless of whether root owns them or root belongs to an associated group.

Is this not the case?
Yes and no, root does have full control over the filesystem but for things to work fluidly it should have the correct perms on the files/folders by default.

Try creating a file with perms 000 and vi into it as root. It will not let you write it with the default ":wq" and you must invoke the ":wq!" to force write as the root user. For daemons and other things that run in the background having the correct permissions by adding the root user to its group allows it to execute without any error.
 
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Old 08-06-2012, 04:37 PM   #5
NotionCommotion
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Thanks again Kustom42. Makes total sense.

Not a bad question, though, for a newbie
 
Old 08-08-2012, 02:20 PM   #6
Kustom42
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Wink

Quote:
Originally Posted by NotionCommotion View Post

Not a bad question, though, for a newbie
The only bad questions are the ones you don't ask
 
  


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