cd ejection

[Sébastien Bonnefoy]

Norman Silverstone wrote:

>On Tue, 2005-04-12 at 19:11 +0100, Norman Silverstone wrote:
>  
>
>>There are 2 users on my machine my wife and myself. My wife had been
>>using the computer earlier today and when she had finished I decided,
>>for the first time, to change to my desktop using Applications-> System
>>Tools-> New login. Some time later I came to eject a CD from the drive
>>and could not do so although only about half an hour before I had been
>>able to. The error message told me that only my wife could eject the CD.
>>Therefore, I changed desktops, this time using System-> Log Out and then
>>ejected the CD. I am using Hoary and this has never happened to me
>>before. Could someone please explain to me what is going on and why this
>>should happen?
>>
>>Norman 
>>
>>    
>>
>I am disappointed that no one has yet been able to answer the question I
>raised. Perhaps I did not make myself very clear. The problem is that if
>I use 'System -> Log Out' when changing from one user to another there
>is no problem in the user ejecting a CD. However, if 'Applications ->
>System Tools -> New Login' is used to change from one user to another
>then sometimes the user is able to eject a CD and sometimes eject does
>not work. Why?
>
>
>
>  
>
Linux system can have many users connected at the same time. Local users 
(like you and your wife) but also remote ones, via ssh od xdmcp (like 
you did "New Login", but from a remote computer). There is some features 
to disallow users to interract with other ones in an insecure way. One 
of this feature it to allow only the user who mount the cdrom to unmount 
it. Mounting is automatic when you first access the drive and unmounting 
is necessary to eject it. It explains why only your wife was able to 
eject the CD.
To eject the CD anyway, you have been able to go back to your wife's 
session. This can be done by pressing Ctrl-Alt-F7 combo on keyboard. 
Ctrl-Alt-F8 would make you return to your session.

Hope it helps

Sébastien