group.of.nepali.translators team mailing list archive

[Dan Streetman <dan.streetman@xxxxxxxxxxxxx>]

** Changed in: linux (Ubuntu)
     Assignee: Dan Streetman (ddstreet) => (unassigned)

** Changed in: linux (Ubuntu Artful)
     Assignee: Dan Streetman (ddstreet) => (unassigned)

** Changed in: linux (Ubuntu Bionic)
     Assignee: Dan Streetman (ddstreet) => (unassigned)

** Changed in: linux (Ubuntu Xenial)
       Status: New => Won't Fix

** Changed in: linux (Ubuntu Zesty)
       Status: New => Won't Fix

** Changed in: linux (Ubuntu)
   Importance: High => Wishlist

** Changed in: linux (Ubuntu Artful)
   Importance: High => Wishlist

** Changed in: linux (Ubuntu Bionic)
   Importance: High => Wishlist

** Changed in: linux (Ubuntu Bionic)
   Importance: Wishlist => Undecided

** Changed in: linux (Ubuntu Artful)
   Importance: Wishlist => Undecided

** Changed in: linux (Ubuntu)
   Importance: Wishlist => Undecided

** Changed in: linux (Ubuntu)
       Status: In Progress => Won't Fix

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भाषा समायोजकहरुको समूह, which is subscribed to Xenial.
Matching subscriptions: Ubuntu 16.04 Bugs
https://bugs.launchpad.net/bugs/1729573

Title:
  netplan breaks Xen VIF driver

Status in linux package in Ubuntu:
  Won't Fix
Status in nplan package in Ubuntu:
  In Progress
Status in linux source package in Xenial:
  Won't Fix
Status in nplan source package in Xenial:
  New
Status in linux source package in Zesty:
  Won't Fix
Status in nplan source package in Zesty:
  New
Status in linux source package in Artful:
  Won't Fix
Status in nplan source package in Artful:
  In Progress
Status in linux source package in Bionic:
  Won't Fix
Status in nplan source package in Bionic:
  In Progress

Bug description:
  [Impact]

  Some network interfaces on a Xen guest are broken by new behavior
  introduced by netplan.  On a Xen guest instance, when netplan is run
  to 'apply' its configuration, under certain circumstances netplan will
  try to "reset" the interface by unbinding and then re-binding the
  interface driver from the interface, by using the sysfs "bind" and
  "unbind" functions of the driver.  Normally, this results in the
  interface being released and then fully re-initialized by the driver.

  However the Xen VIF driver breaks when this is done.  The internal Xen
  backend state of the interface remains in 'closed' state after the
  driver re-connects to the interface, and attempts to open and use the
  interface result in a kernel Oops in the Xen VIF driver.

  To users, it appears that the interface is unusable because it has an
  all 0 mac address; but if the mac is manually set and the interface
  brought up the driver Oopses as mentioned above.

  This problem makes booting painful because of very long timeouts
  waiting for all network interfaces to start, and affected Xen VIF
  interfaces will of course never complete startup.

  [Fix]

  No fix yet.  Upstream kernel does not appear fixed.

  [Test Case]

  Create a guest instance under a Xen hypervisor (e.g. an AWS instance)
  that has Ubuntu Artful 17.10 installed.  Use only a single interface
  at first when creating it.  Then once it is ready, attach a second
  network interface to the instance.  From inside the instance,
  configure the new interface in netplan (i.e. add a /etc/netplan/
  config for it).  Make sure the new interface is down (netplan does not
  appear to unbind/bind interfaces that are up), and then run:

  $ sudo netplan apply

  or for debug,

  $ sudo netplan --debug apply

  this will unbind and re-bind the second interface, which will then
  have all-0 mac, and will be unusable, as described above.

  [Regression Potential]

  Changes to the Xen VIF driver can result in unusable network
  interfaces, or problems while using Xen VIF interfaces.

  [Other Info]

  Problem appears to exist upstream also.

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