Incomplete shutdown on some LTSP clients (shutdown hangs/freezes)

[John Hupp]

Some updates on this problem:

The problem is not confined to LTSP clients.  I booted an Lubuntu Live 
CD on one of the affected clients and found that it hung during shutdown 
also.

----------------------------

The problem is also not Gnome-specific, as someone suggested.

I downloaded Kubuntu 12.04 (uses KDE rather than Gnome) and made a Live DVD.

On one of the clients with the shutdown problem, I booted the Live DVD.  
I didn't have a working pointer (500 MHz Celeron and 256 MB, so maybe 
not enough resources), but the "sudo poweroff" command from a console 
window resulted in shutdown hanging after "System halted" was reported 
onscreen, and I had to force the machine off.

----------------------------

I also played with the BIOS Power Control settings to no effect on one 
of the affected machines.  For "ACPI Aware O/S: Yes/No" and "Power 
Management/APM: Enabled/Disabled" I tried all four permutations of BIOS 
settings and all resulted in the same hung shutdown.

There were also other settings: "Power Button Function: On/Off," 
"Suspend Time Out: Enabled/Disabled" and <various devices>: 
"Monitor/Ignore," but I took those to be irrelevant.


On 8/25/2012 2:30 PM, John Hupp wrote:
> On my Lubuntu and Edubuntu 12.04 LTSP test networks, I find that some 
> clients do not shut down completely.
>
> On the Lubuntu network, one eMachine client stops at a black-and-white 
> text screen that says:
>     Ubuntu 12.04
>     .... * Asking all remaining processes to terminate ...
>     [255.161402] SysRq : Power off
>     [255.173722] Power down.
>           [OK]
>     [255.280060[ SysRq : Power Off
>     [255.280220] Power down.
>     * All processes ended within 1 seconds ....    [OK]
> A simple press of the power button does not turn off the machine at 
> that point.  I have to press and hold it 5 seconds or so.
>
> Also on the Lubuntu network, an HP stops at the same screen, but a 
> simple press of the power button turns it off.
>
> A Dell on the Lubuntu networks shuts off cleanly and completely within 
> a few seconds.
>
> ---------------------
>
> On the Edubuntu network, all clients have to invoke Shutdown from the 
> desktop and from the login screen.  After choosing Shutdown from the 
> desktop (and then presenting a dialog for Shutdown or Restart), it 
> drops back to the login screen, and there one chooses Preferences: 
> Shutdown.  [Very tedious, but that's not my real interest in this 
> post.  And as a footnote, the server shuts down cleanly after the two 
> clicks on the desktop.
>
> But regarding specific client machine behavior on the Edubuntu 
> network, the above eMachine hangs at a black screen after Preferences: 
> Shutdown from the login screen.  I forgot to make a note of whether a 
> simple press of the power button shuts it off from here, or whether a 
> press-and-hold was required as it was on the Lubuntu net.
>
> The above HP hangs at a white screen after Preferences: Shutdown from 
> the login screen.  A simple press of the power button shuts it off 
> from here.
>
> The above Dell shuts down cleanly after Preferences: Shutdown from the 
> login screen.
>
> ---------------------
>
> One other behavior that was of interest to me but that I did not 
> thoroughly document was that even on machines where Shutdown hangs, it 
> seems generally to be the case that Restart does not hang.  The 
> machine proceeds smoothly to POST and reboot.
>
> ---------------------
>
> So I am wondering if I can get all the clients to shut down cleanly 
> via the interface Shutdown commands.
>
> If not, is there a script that will produce a clean shutdown?
>
> Or failing that, can I insert a splash screen at the end of the 
> shutdown process something like Windows 95/98 used on machines where 
> it could not execute a complete shutdown automatically?  (The screen 
> said something like "It is now safe to turn off your computer.")
>
> Speaking of Windows 95/98's shutdown process, I recall that the issue 
> had to do with power management drivers not fully supporting the 
> hardware on some motherboards, or not finding the hardware that power 
> management did fully support.  But beyond that, it was possible to 
> not-install/uninstall/disable power management on machines that did 
> support full shutdown, then install/reinstall/re-enable power 
> management but not recover the ability to do a full shutdown.  So it 
> wasn't always just a question of supported hardware.
>
> Also regarding Win 9x, that splash screen may have been an integrated 
> part of all shutdowns.  I recall seeing it flash on-screen for a split 
> second even on machines that were on their way to a full automatic 
> shutdown.
>
>
>

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