it appears that my symptoms also relate to this bug report. however, i'd like to add that the feedback provided by the system, at least in my particular case, is extremely unhelpful. i think it can be better.
i have a very minimal virtual guest, running 16.04. it has a "physical" wired connection, and an nfs mount in fstab: >cat /etc/fstab # /etc/fstab: static file system information. # # Use 'blkid' to print the universally unique identifier for a # device; this may be used with UUID= as a more robust way to name devices # that works even if disks are added and removed. See fstab(5). # # <file system> <mount point> <type> <options> <dump> <pass> proc /proc proc nodev,noexec,nosuid 0 0 LABEL=root / ext4 errors=remount-ro 0 1 LABEL=var /var ext4 defaults 0 2 LABEL=swap none swap sw 0 0 10.128.35.251:/foo_example_com /home/foo.example.com nfs rw,hard,intr 0 0 >cat /etc/network/interfaces # This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto eth0 iface eth0 inet static address 10.101.27.31/24 gateway 10.101.27.1 in this case, there is no [perceptible] delay during shutdown, but a lengthy delay at boot, while system waits for mounting to succeed/timeout. when there are network problems, the nfs mount attempt cannot succeed, and this is when the system says "a start job is running for raise network interfaces", while it sits for five minutes, yet ultimately proceeds, with a perfectly operational network interface. this sucks. while the root cause here, in terms of the actual problem, is that 1] the nfs mount obviously fails, and 2] the timeout for this failure is [imho] too long, the troubleshooting process to determine this was made much longer than it should have been due to the poor feedback about what was actually happening. in this particular case, the system should, at the minimum, at least tell the operator that there is a mount attempt waiting, and ideally, provide some actual detail about what mount attempt in particular. saying "a start job is running for raise network interfaces" is woefully inadequate. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, 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: Confirmed Status in systemd package in Ubuntu: Confirmed 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 -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp