CentOS - Aug 2015 - Shutdown hangs on "Unmounting NFS filesystems"

Once the system gets into this state, the only remedy is a forced
power-off.  What seems to be happening is that an NFS filesystem that
auto-mounted over a WiFi connection cannot be unmounted because the
WiFi connection is enabled only for my login and gets torn down when
my UID is logged off.

Any suggestions on how I can configure things to avoid this?  I
really don't want to expose my WPA2 key by making the connection
available to all users.

-- 
Bob Nichols     "NOSPAM" is really part of my email address.
                 Do NOT delete it.

On 08/30/2015 04:20 PM, Robert Nichols wrote:
> Once the system gets into this state, the only remedy is a forced
> power-off.  What seems to be happening is that an NFS filesystem that
> auto-mounted over a WiFi connection cannot be unmounted because the
> WiFi connection is enabled only for my login and gets torn down when
> my UID is logged off.
>
> Any suggestions on how I can configure things to avoid this?  I
> really don't want to expose my WPA2 key by making the connection
> available to all users.
Oops, forgot to mention that this is CentOS 6.7.

-- 
Bob Nichols     "NOSPAM" is really part of my email address.
                 Do NOT delete it.

On Sun, 30 Aug 2015 16:20:21 -0500
Robert Nichols wrote:
> Once the system gets into this state, the only remedy is a forced
> power-off.  What seems to be happening is that an NFS filesystem that
> auto-mounted over a WiFi connection cannot be unmounted because the
> WiFi connection is enabled only for my login and gets torn down when
> my UID is logged off.
> 
> Any suggestions on how I can configure things to avoid this?  I
> really don't want to expose my WPA2 key by making the connection
> available to all users.
Perhaps you could unmount that share when you log off by putting a umount
command into the appropriate file.

The definition of "appropriate file" varies depending on what DE
you're using.


-- 
MELVILLE THEATRE ~ Real D 3D Digital Cinema ~ www.melvilletheatre.com

On 8/30/2015 2:20 PM, Robert Nichols wrote:
> Once the system gets into this state, the only remedy is a forced
> power-off.  What seems to be happening is that an NFS filesystem that
> auto-mounted over a WiFi connection cannot be unmounted because the
> WiFi connection is enabled only for my login and gets torn down when
> my UID is logged off.
>
> Any suggestions on how I can configure things to avoid this?  I
> really don't want to expose my WPA2 key by making the connection
> available to all users. 
my experience is A) NFS doesn't like unreliable networks, and B) WiFi 
isn't very reliable.

perhaps using the 'soft' mount option will help, along with intr ?

-- 
john r pierce, recycling bits in santa cruz

On Sun, Aug 30, 2015 at 04:20:21PM -0500, Robert Nichols
wrote:
> Once the system gets into this state, the only remedy is a forced
> power-off.  What seems to be happening is that an NFS filesystem that
> auto-mounted over a WiFi connection cannot be unmounted because the
> WiFi connection is enabled only for my login and gets torn down when
> my UID is logged off.
> 
> Any suggestions on how I can configure things to avoid this?  I
> really don't want to expose my WPA2 key by making the connection
> available to all users.
I didn't think that making the connection available to all users
had security ramifications regarding your wifi password... 
if someone else logs in and uses the wifi, they still need the
root password to access the wireless configuration, don't they?


Fred
-- 
---- Fred Smith -- fredex at fcshome.stoneham.ma.us
-----------------------------
                    The Lord detests the way of the wicked 
                  but he loves those who pursue righteousness.
----------------------------- Proverbs 15:9 (niv) -----------------------------

On 08/30/2015 04:45 PM, John R Pierce wrote:
> On 8/30/2015 2:20 PM, Robert Nichols wrote:
>> Once the system gets into this state, the only remedy is a forced
>> power-off.  What seems to be happening is that an NFS filesystem that
>> auto-mounted over a WiFi connection cannot be unmounted because the
>> WiFi connection is enabled only for my login and gets torn down when
>> my UID is logged off.
>>
>> Any suggestions on how I can configure things to avoid this?  I
>> really don't want to expose my WPA2 key by making the connection
>> available to all users.
>
> my experience is A) NFS doesn't like unreliable networks, and B) WiFi
> isn't very reliable.
>
> perhaps using the 'soft' mount option will help, along with intr ?
Making use of the "intr" option would require that the umount process
have the console as its controlling tty.  AFAICT, having been invoked
from the init process, it has _no_ controlling tty.  Hard to send a
SIGINT that way.

Really, I don't think the problem is specific to WiFi.  I believe I'd
run into the same thing for any network connection that was not marked
"Available to all users" in NetworkManager.

-- 
Bob Nichols     "NOSPAM" is really part of my email address.
                 Do NOT delete it.

On Sun, Aug 30, 2015 at 04:20:21PM -0500, Robert Nichols
wrote:
> Any suggestions on how I can configure things to avoid this?  I
> really don't want to expose my WPA2 key by making the connection
> available to all users.
How are you mounting the volume?  Are you using autofs?

-- 
Jonathan Billings <billings at negate.org>

On 08/30/2015 04:32 PM, Frank Cox wrote:
> On Sun, 30 Aug 2015 16:20:21 -0500
> Robert Nichols wrote:
>
>> Once the system gets into this state, the only remedy is a forced
>> power-off.  What seems to be happening is that an NFS filesystem that
>> auto-mounted over a WiFi connection cannot be unmounted because the
>> WiFi connection is enabled only for my login and gets torn down when
>> my UID is logged off.
>>
>> Any suggestions on how I can configure things to avoid this?  I
>> really don't want to expose my WPA2 key by making the connection
>> available to all users.
>
> Perhaps you could unmount that share when you log off by putting a umount
command into the appropriate file.
>
> The definition of "appropriate file" varies depending on what DE
you're using.
Thanks for the suggestion. I'm using Gnome, and created an
executable file /etc/gdm/PostSession/autofsNFS containing:

   #!/bin/bash
   if grep -q ':.* nfs[234]\? ' /proc/mounts; then
       if [ -r /var/run/autofs.pid ]; then
	  Pid=$(</var/run/autofs.pid)
	  [ -n "$Pid" ] && kill -USR1 $Pid
       fi
   fi

That sends a SIGUSR1 to the automount process if there are any
remote NFS mounts listed in /proc/mounts.  It seems to do the
trick.

-- 
Bob Nichols     "NOSPAM" is really part of my email address.
                 Do NOT delete it.