[Samba] valid users VS users in conf

[DNK]

Hi there,

Samba 3.0.33-3.7.el5
Centos 5.3

For some time now I have been using the following on my shares:

valid users = @group



For some reason, my samba just up and crapped out over the weekend...

When trying to mount the drive (Win XP), it just keeps asking for the  
credentials.
When trying from OS X, I get "A volume failed to mount" error.

When attempting with the smbclient I get:
tree connect failed: NT_STATUS_ACCESS_DENIED

I was watching my log file with a tail -f and NOTHING is logged there  
when it fails.


I did some searching around and some posts for similar issues people  
suggest using:

users = @group

for the shares.

I tried that and it started working again. There were no updates done  
to the system, and my system has been working with the "valid users =  
@group" for years.

Why would this happen?

Is there any disadvantage or security concern by using the "users =  
@group" style?

Ideas?

Dustin