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

[John Hupp]

Good news!

Richard Doyle from the LTSP mail list posted that I can add acpi=force 
to the end of the append command in 
/var/lib/tftpboot/ltsp/<arch>/pxelinux.cfg/default.

I did this on my Edubuntu and Lubuntu LTSP servers, and all clients 
tested then shut down fully.

The only remaining problem, which seems to this newbie like a bug rather 
than a feature, is what Richard Doyle points out (I have not it 
confirmed here, but his other info was dead-on-center): running 
ltsp-update-image will restore the original 
/var/lib/tftpboot/ltsp/<arch>/pxelinux.cfg/default, so this and any 
other edits are wiped out.

And I still have a related secondary question: Since acpi=force 
indicates that ACPI has to run on the client and not just on the server, 
how can I verify that ACPI is indeed running on the client?  Someone 
suggested looking at the output of dmesg on the client for results that 
contain "ACPI," but it seems to me that this will just report the boot 
messages from the server, not the client.

A big thank-you to all who contributed to solving the original primary 
problem.  Special thanks to Richard Doyle from the LTSP mail list and 
Steve Yorvyk from the Lubuntu list.

On 9/2/2012 3:54 PM, John Hupp wrote:
> 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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