I keep doing some experiments (with Dell/HP laptops) and there are some
conclusions currently:

1. why does the issue happen (not real root cause)
Due to local-fs.target, the fstab-generator automatically adds dependencies of 
type Before= to all mount units that refer to local mount points for this 
target unit. In addition, it adds dependencies of type Wants= to this target 
unit for those mounts listed in /etc/fstab that have the auto mount option 
set[1].
Therefore, the emergency shell is triggered by local-fs.target which is 
dependent on failures of several systemd mounts.

2. provides 2 approaches for workaround fix

1) append "systemd.mask=dev-hugepages.mount systemd.mask=dev-
mqueue.mount systemd.mask=sys-fs-fuse-connections.mount systemd.mask
=sys-kernel-config.mount systemd.mask=sys-kernel-debug.mount
systemd.mask=tmp.mount" into kernel boot options.

2) add "toram" into kernel boot options.
it would completely decompress the filesystem into RAM, which requires 3-4x 
more RAM, and is hence undesired[2].

3. trade-off between workarounds
Until we find the solution, the better way to workaround is to use "toram" to 
fix the issue. The reason behind it is we not only get speed-up the 
installation but also avoid the unstable network with nfs, despite requiring 
more RAM.

4. The real solution concern
I think the solution may be more complicated if we really want to fix, and 
ideally we have to consider the cases of normal (e.g. from usb stick) and nfs 
mount to satisfy the conditions to avoid systemd failure with dependencies or 
protocol.

[1] https://www.freedesktop.org/software/systemd/man/systemd.special.html
[2] https://wiki.ubuntu.com/BootToRAM

-- 
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/1755863

Title:
  netbooting the bionic live CD over NFS goes straight to maintenance
  mode :

Status in casper package in Ubuntu:
  Confirmed
Status in systemd package in Ubuntu:
  Confirmed

Bug description:
  netbooting the bionic live CD[1] over NFS goes straight to maintenance
  mode :

  [1] http://cdimage.ubuntu.com/daily-live/current/

  # casper.log
  Begin: Adding live session user... ... dbus-daemon[568]: [session uid=999 
pid=568] Activating service name='org.gtk.vfs.Daemon' requested by ':1.0' 
(uid=999 pid=569 comm="" label="unconfined")
  dbus-daemon[568]: [session uid=999 pid=568] Successfully activated service 
'org.gtk.vfs.Daemon'
  dbus-daemon[568]: [session uid=999 pid=568] Activating service 
name='org.gtk.vfs.Metadata' requested by ':1.0' (uid=999 pid=569 comm="" 
label="unconfined")
  fuse: device not found, try 'modprobe fuse' first
  dbus-daemon[568]: [session uid=999 pid=568] Successfully activated service 
'org.gtk.vfs.Metadata'

  (gvfsd-metadata:580): GUdev-CRITICAL **: 16:28:56.270:
  g_udev_device_has_property: assertion 'G_UDEV_IS_DEVICE (device)'
  failed

  (gvfsd-metadata:580): GUdev-CRITICAL **: 16:28:56.270: 
g_udev_device_has_property: assertion 'G_UDEV_IS_DEVICE (device)' failed
  A connection to the bus can't be made
  done.
  Begin: Setting up init... ... done.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/casper/+bug/1755863/+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

Reply via email to