1

[ubuntu] Permissions and NFS mounts

view story
linux-howto

http://ubuntuforums.org – I've created an NFS share on my ubuntu 12.04 machine and am now trying to properly set up permissions on it. I want to allow access to the share only to members of a specific group, in this case cerberusaccess I got it working on the ubuntu machine by creating the group, adding the proper users to it, and then changing the group of the directory to cerberusaccess and setting its permissions to rwxrwx---, which (as I understand it) makes it read/writable by the owner and group members, but no one else. Now I want to have the same privileges from my os x laptop, but I just get permission d (Hardware)

xskl's picture
Submitted by xskl on 09/10/2012

Stories similar to [ubuntu] Permissions and NFS mounts

I have an Ubuntu 10.10 server running, which serves as a PDC, on which a number of windows 7 clients log on.

I wanted to create a share on which users can create and delete files, but not edit them.

I have a test setup with two user groups: group-a and group-b, and a single samba-share with

path = /data/share read only = no create mask = 770

Certain users are in both group-a and group-b and have group-a as their primary group.

I encounter a strange problem on a unix/linux machine:

I'm member of a group, let's call it group A and a certain file (which has a different owner) belongs to group A as well. The permissions of that file are

-rw-rw----

so I'd expect I should be able to open that file, but I am not: I'll get the "Permission denied" error message when I try to look at the file's content (using cat).

I think I rather understand how file permissions work in linux. However, I don't really understand why they are split into three levels and not into two.

I'd like the following issues answered:

Is this deliberate design or a patch?

I'm running a duel boot/partition machine with Ubuntu 12.04 and Windows 7. On Ubuntu OS, I wanted to change the permissions in one of my directories so could extract files into that directory. In the terminal I entered chmod -R 777 /usr/share/icons which gives the owner, group, global read, write, and execute permissions.

I have a directory in which collaborative files / directories are stored. Say directory abc is owned by root and the group is project-abc.

I have a security mystery :) Effective permissions tab shows that a few sampled users (IT ops) have any and all rights (all boxes are ticked). The permissions show that Local Administrators group has full access and some business users have too of which the sampled users are not members of.

Running Samba on Ubuntu Server. I have a share that is accessible to anyone on the network. The shared directory is set to 775.

I want Windows users that are joined to a particular workgroup to get group permissions, in this case 7, while everyone else get's global permissions, in this case 5.

Is this possible?

This is such an elementary question, and I can't believe I've been using Unix (Linux and Mac) for over 5 years without knowing this!

The root user has group id 0 and user id 0. Hence lower group ids have more permission. The question is, if I want to create an administrator group, where all members have the same rights as the root group, is that a safe practice?