[Bug 1594658] [NEW] diskless setup with nfs mounted home hangs on shutdown/reboot

[Sergey Frolov]

Public bug reported:

Ubuntu 16.04 fresh install hangs when shutting down.
The system is diskless PXE-booted with a couple of nfs mounted directories including homedir.

As I have no persistent storage whatsoever, I don't have any logs, but
in debug-shell, running journalctl -f I can see that it hangs at

[   *] (1 of 2) A stop job running for Raise Network Interfaces (10s / 1min 30s)Jun 20 20:23:05 $hostname kernel: nfs: server $nfs-ip-address not responding, still trying
Jun 20 20:23:05 $hostname kernel: nfs: server $nfs-ip-address not responding, still trying
Jun 20 20:23:14 $hostname kernel: nfs: server $nfs-ip-address not responding, still trying
Jun 20 20:24:08 $hostname kernel: nfs: server $nfs-ip-address not responding, still trying

Second job in "(1 of 2)" is thermald, turning it off does not fix the problem.
Also, this counter "(10s / 1min 30s)" stops visually updating.

server $nfs-ip-address is not responding, because, all network
interfaces are already down at this point.

I am not exactly sure why this happens. Looks like there is a wrong
ordering of shutdown of systemd services, which bring down interfaces
before something nfs-related, but I am not sure if that's the reason of
hanging.


Workaround that fixes the problem:
In /lib/systemd/system/networking.service
comment following line:
ExecStop=/sbin/ifdown -a --read-environment

** Affects: nfs-utils (Ubuntu)
     Importance: Undecided
         Status: New

** Affects: systemd (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: diskless hangs networking nfs reboot shutdown systemd

** Also affects: nfs-utils (Ubuntu)
   Importance: Undecided
       Status: New

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to systemd in Ubuntu.
https://bugs.launchpad.net/bugs/1594658

Title:
  diskless setup with nfs mounted home hangs on shutdown/reboot

Status in nfs-utils package in Ubuntu:
  New
Status in systemd package in Ubuntu:
  New

Bug description:
  Ubuntu 16.04 fresh install hangs when shutting down.
  The system is diskless PXE-booted with a couple of nfs mounted directories including homedir.

  As I have no persistent storage whatsoever, I don't have any logs, but
  in debug-shell, running journalctl -f I can see that it hangs at

  [   *] (1 of 2) A stop job running for Raise Network Interfaces (10s / 1min 30s)Jun 20 20:23:05 $hostname kernel: nfs: server $nfs-ip-address not responding, still trying
  Jun 20 20:23:05 $hostname kernel: nfs: server $nfs-ip-address not responding, still trying
  Jun 20 20:23:14 $hostname kernel: nfs: server $nfs-ip-address not responding, still trying
  Jun 20 20:24:08 $hostname kernel: nfs: server $nfs-ip-address not responding, still trying

  Second job in "(1 of 2)" is thermald, turning it off does not fix the problem.
  Also, this counter "(10s / 1min 30s)" stops visually updating.

  server $nfs-ip-address is not responding, because, all network
  interfaces are already down at this point.

  I am not exactly sure why this happens. Looks like there is a wrong
  ordering of shutdown of systemd services, which bring down interfaces
  before something nfs-related, but I am not sure if that's the reason
  of hanging.

  
  Workaround that fixes the problem:
  In /lib/systemd/system/networking.service
  comment following line:
  ExecStop=/sbin/ifdown -a --read-environment

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/nfs-utils/+bug/1594658/+subscriptions