[ale] too many logins

[Todor Fassl]

The biggest problem is that the login screen gets crowded with the names 
of other users who have logged in recently. Students don't see the box 
to enter a different user ID so they reboot the machine which kills off 
any  matlab or sage jobs somebody else might have started. After a 
reboot, the login screen has maybe one or two names on it. There must be 
some fairly complex algorithm for determining who gets on that list 
because I cannot see a pattern.



On 11/11/2014 12:15 PM, Ed Cashin wrote:
> I was reading kind of fast, but I'm not sure you pointed out any
> specific ill effects.  I'd expect the kernel to page to disk the pages
> in RAM associated with the unused sessions.  So once all the matlab
> state (etc.) is on the swap partition, there'd be little cost associated
> with a stale login as long as you have plenty of swap space.  Maybe
> everything is already fine now?
>
> On Tue, Nov 11, 2014 at 11:55 AM, Todor Fassl <fassl.tod at gmail.com
> <mailto:fassl.tod at gmail.com>> wrote:
>
>     Suggestions?
>
>
>
>
>     On 11/11/2014 10:47 AM, JD wrote:
>
>         Is there a question?
>
>         On 11/11/2014 11:32 AM, Todor Fassl wrote:
>
>             I have a problem in a lab I am responsible for. The lab has
>             7 debian stable
>             machines. Students log in to check mail, browse the web,
>             etc. But they
>             frequently walk away without logging out. Soon enough, the
>             screen saver comes on
>             and the next person sits down and logs in as another user.
>             Often, the first
>             person comes back hours late or the next day and logs in a
>             second time. Some of
>             these machines have the same user logged in 5 or 6 times.
>
>             The problem is that some of these students start matlab,
>             sage, or magma jobs
>             before they walk away from the workstation. Those are
>             legitimate jobs and should
>             not be killed.  In fact, sometimes students ssh to these
>             machines and run
>             computations. It's kind of a bad idea but I'd rather not
>             tell them not to do
>             that. Otherwise, I'd just have the machines reboot
>             themselves every  night.
>
>             We used to use a tool called timeoutd but it seems to have
>             been removed from the
>             debian stable and ubuntu archives.  I was never able to get
>             it to work right
>             anyway. Students would complain that their jobs had been
>             killed or that they
>             were logged out while they were typing away. At the same
>             time, I could see that
>             other users were still logged in after days/weeks of
>             inactivity. I am not sure
>             the problem really was with timeoutd because finger often
>             gave me weird
>             results.I'm not sure linux was giving timeoutd correct data
>             to work with.
>
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>
> --
>    Ed Cashin <ecashin at noserose.net <mailto:ecashin at noserose.net>>
>
>
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