[ale] Lab Workstation Mystery

DJ-Pfulio djpfulio at jdpfu.com
Wed Apr 20 15:32:10 EDT 2016


Stuff like this is a reason why running non-LTS isn't recommended, unless
absolutely required due to new hardware that hasn't been backported yet. There
are other reasons NOT to touch non-LTS releases.

"New" != Better

BTW, Ubuntu 16.04 LTS release is TOMORROW.  I'll be waiting a few months before
deployment (maybe 2 more yrs), but will start playing with the server version
Friday. I don't touch desktop releases from Canonical anymore.  All the hassles
just aren't worth the effort.

IMHO, systemd still needs a few more years of painful use by others before it
will be ready enough for my needs.  14.04 barely has any systemd, but some
power-related settings are controlled by it.

Of course, I'm not everyone else. Many thanks to folks chasing "new" - I did my
time in the 1990s doing that.

On 04/20/2016 02:00 PM, Todor Fassl wrote:
> I verified that if you log in and then just log back out immediately, those same
> 4 processes remain running, systemd, sd-pam, ibus-daemon, and ibus-dconf. I
> don't have a plain ubuntu 15.10 system handy but I'll bet it does the same
> thing. Anybody have a machine like that? Login at the console, log out, ssh to
> the machine as another user, and see if there are any processes still running
> for the user who just logged out.
> 
> I tried switchng a machine to use gdm instead of lightdm, no joy.  I think I'm
> logging in via gnome. I can try unity too.
> 
> I think it's a systemd issue. In fact, I think it's a "feature" of systemd. It
> messes up autofs though.
> 
> 
> 
> 
> 
> On 04/20/2016 12:31 PM, Jim Kinney wrote:
>> Anyone using screen, tmux or nohup?
>> On Wed, 2016-04-20 at 11:52 -0500, Todor Fassl wrote:
>>> I posted about this problem a couple of weeks ago and still have not
>>> figured it out. The problem is that on a group of machines running
>>> ubuntu 15.10, after a period of time, mounting home directories via
>>> NFS
>>> hangs. Attempting to mount or unmount home directories via NFS
>>> simply
>>> hangs. Eventually, the root filesystem getsremounted read-only and
>>> the
>>> machine becomes unusable even as a local user. One thing I've
>>> discovered
>>> since my first post about this is that when end-users log out, some
>>> processes do not get killed off. The automounter can't umount the
>>> home
>>> directory because the user still has some processes running.
>>> Eventually,
>>> the machine has several home directories mounted via NFS for users
>>> who
>>> are no longer logged in. I am thinking that what is happening is
>>> that
>>> eventually this causes NFS to get wedged which in turn leads to the
>>> kernel freaking out. Or something. Here is an example of the output
>>> from
>>> listing the processes for a user who has logged out:
>>>
>>> # ps -u enduser1
>>>       PID TTY          TIME CMD
>>>    101794 ?        00:00:00 systemd
>>>    101795 ?        00:00:00 (sd-pam)
>>>    103049 ?        00:00:00 ibus-daemon
>>>    103057 ?        00:00:00 ibus-dconf
>>>
>>>
>>> So frequently, even though a user has logged out days ago, the
>>> systemd
>>> and ibus-deamon might still be running. I am thinking after enough
>>> time,
>>> these things mess up the nfsv4 kernel module which eventually messes
>>> up
>>> the kernel itself.
>>>
>>> But why would logging out *not* killoff all of an end-user's
>>> processes?
>>>
>>>
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> 



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