[Users] Host shutdown hangs on vz service stop

[Gordan Bobic]

Gregor at HostGIS wrote:
>> That does, indeed, sound very familiar.
>> I just vzcfgvalidate-d my config files and it threw up no problems or 
>> errors. :-/
> 
> Aww, darn. My thread is here:
> http://bugzilla.openvz.org/show_bug.cgi?id=1345
> 
> It's embarrassing, though a relief, that by the time I had opened the 
> ticket the problem never happened again. We checked vzcfgvalidate, 
> checked vzctl-libs versions, and changed to other kernels but it never 
> happened again. So, we never positively identified a cause and solution.
> 
> The only changes I had made in previous months were to upgrade the 
> kernel (we use 2.6.24, now at ovz009.1) and to fix the config flaws. So 
> if you're not seeing config issues, maybe a kernel upgrade?
> 
> They had also suggested updating vzctl and vzctl-libs, and verifying 
> that both packages' versions matched. Though this wasn't our issue, it 
> was one thing they suggested during hunting this bug.

I just a bit more testing, and it doesn't seem to end with a time-out
message at service shutdown. The service _eventually_ stops but it takes
a minute or so. Issuing halt in the CT takes about 5 seconds, after
which issuing vzctl stop takes about 2, and after that service vz stop
is instantaneous. I'd be curious to learn how the shutdown process works
when initialized from the HN. I'm guessing this is somehow related to
the difference between issuing "halt" and "shutdown -h now" in the CT
("shutdown -h now" seems to take a lot longer).

Gordan