Owner of shared directory

directoryfilesgrouppermissions

The directory /path/to/dir is meant to be used by any member of the group examplegroup. All the members of this group should be able to modify the content of the directory without limitations (read/write files, create files, run executables).

It is obvious that the group owner of the directory must be examplegroup.

But what could be an appropriate choice for the user owner of the directory? root, one of the users of the examplegroup, nobody, or someone else?

Best Answer

Whoever is the owner will be able to change permissions of the directory, which would allow him to remove the group-write permission. So it should be a user who is trusted with that ability. It could be the group leader, for instance. Or it could be someone outside the group if none of them are so trusted.

If you set it to root, then only system administrators will be able to change directory permissions. But if permissions never need to change, this shouldn't be a problem.

Related Solutions

Default directory permissions over NFS

How are you disseminating the user/group info that's contained in /etc/passwd and /etc/group? You typically need to use NIS, LDAP, or rsync the /etc/passwd /etc/group files to all the machines that are automounting these mounts. Otherwise the clients know nothing of the permissions on the filesystem.

You might want to peruse the NIS Howto.

Granting write permissions to a group to a folder

Granting 775 permissions on a directory doesn't automatically mean that all users in a certain group will gain rwx access to it. They need to either be the owner of the directory or to belong to the directory's group:

$ ls -ld some_dir
drwxrwxr-x 2 alex consult 4096 Feb 20 10:10 some_dir/
              ^     ^
              |     |_____ directory's group
              |___________ directory's owner

So, in order to allow both alex and ben to have write access to some_dir, the some_dir directory itself must belong to the consult group. If that's not the case, the directory's owner (alex in your example), should issue the following command:

$ chgrp consult some_dir/

or to change group ownership of everything inside the directory:

$ chgrp -R consult some_dir/

This will only work if alex is a member of the consult group, which seems to be the case in your example.

This will not allow ben to access all of alex's directories for two reasons:

Not all of alex's directories will belong to the consult group
Some of alex's directories may belong to the consult group but alex may not have chosen to allow rwx group access to them.

In short, the answer depends both on group ownership and on the group permission bits set for the directory.

All of this is provided you don't use any additional mandatory access control measures on your system.

Best Answer

Related Solutions

Default directory permissions over NFS

Granting write permissions to a group to a folder

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