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[Martin Pitt <martin.pitt@xxxxxxxxxx>]

I finally understand what's going on. This started a few weeks ago when
we got lxcfs. What happens:

 - lxcfs' upstart job and systemd unit have this gem:
     sed -i "/^lxcfs \/var\/lib\/lxcfs fuse.lxcfs/d" /etc/mtab
  
   This will turn /etc/mtab into a file if it was a symlink to /proc/mounts. But these days we actually want it to be a symlink, as /etc/mtab as a static file is just a braindead and broken concept.

 - When systemd starts up, it parses existing mounts (via /etc/mtab) and
creates mounts for them. This will include all the old mounts from the
previous boot due to the previous issue. That's what triggers all these
"dead -> mounted" transitions for all mounts right at the beginning of
boot. But as the backing devices of them aren't discovered/there yet,
but a mount unit is always bound to its underlying device unit, systemd
cleans them up, i. e. stops them. This is usually meant for cleaning
stale mounts from unplugged devices; it also makes sense here as these
mounts indeed are not mounted at the moment.

 - Later on, the fstab generated mounts are actually being executed. But
this races with the async mount cleanup handler from above, so depending
on the particular machine, installed services, and current wind speed it
may happen at a harmless (before the fstab mounts) or at a bad time
(after the fstab mounts).

 - Even later, our debian-fixup.service transitions /etc/mtab from a
file to a symlink. This is supposed to be an one-time migration, but
lxcfs always reverts that during shutdown.

** Also affects: lxcfs (Ubuntu)
   Importance: Undecided
       Status: New

** Changed in: lxcfs (Ubuntu)
   Importance: Undecided => High

** Changed in: lxcfs (Ubuntu)
       Status: New => Triaged

** Changed in: lxcfs (Ubuntu)
     Assignee: (unassigned) => Martin Pitt (pitti)

** Changed in: systemd (Ubuntu)
       Status: Confirmed => In Progress

** Changed in: lxcfs (Ubuntu)
       Status: Triaged => In Progress

** Summary changed:

- systemd unmounts partitions from fstab
+ systemd unmounts partitions from fstab when lxcfs is installed

** Summary changed:

- systemd unmounts partitions from fstab when lxcfs is installed
+ systemd unmounts mounted filesystems when lxcfs is installed

-- 
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Touch seeded packages, which is subscribed to systemd in Ubuntu.
https://bugs.launchpad.net/bugs/1419623

Title:
  systemd unmounts mounted filesystems when lxcfs is installed

Status in lxcfs package in Ubuntu:
  In Progress
Status in systemd package in Ubuntu:
  In Progress

Bug description:
  This seems to have been triggered by the glib update on ubuntu-desktop
  ppa. No partitions from fstab (apart from root of course) are getting
  mounted at boot. This is just a little problematic when /home is on a
  different partition!

  ProblemType: Bug
  DistroRelease: Ubuntu 15.04
  Package: systemd 218-7ubuntu1 [modified: lib/systemd/system/ifup@.service]
  ProcVersionSignature: Ubuntu 3.18.0-12.13-generic 3.18.4
  Uname: Linux 3.18.0-12-generic x86_64
  NonfreeKernelModules: nvidia
  ApportVersion: 2.16-0ubuntu1
  Architecture: amd64
  CurrentDesktop: GNOME
  Date: Mon Feb  9 17:30:12 2015
  InstallationDate: Installed on 2012-09-23 (869 days ago)
  InstallationMedia: Ubuntu GNOME Remix 12.10 "Quantal Quetzal" - Alpha amd64(20120922)
  MachineType: Gigabyte Technology Co., Ltd. P67A-UD3R-B3
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.18.0-12-generic root=UUID=71eeb904-068b-41c2-9d34-59365ca4c3ad ro quiet splash init=/lib/systemd/systemd systemd.log_level=debug
  SourcePackage: systemd
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 03/21/2012
  dmi.bios.vendor: Award Software International, Inc.
  dmi.bios.version: F9
  dmi.board.name: P67A-UD3R-B3
  dmi.board.vendor: Gigabyte Technology Co., Ltd.
  dmi.board.version: x.x
  dmi.chassis.type: 3
  dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
  dmi.modalias: dmi:bvnAwardSoftwareInternational,Inc.:bvrF9:bd03/21/2012:svnGigabyteTechnologyCo.,Ltd.:pnP67A-UD3R-B3:pvr:rvnGigabyteTechnologyCo.,Ltd.:rnP67A-UD3R-B3:rvrx.x:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvr:
  dmi.product.name: P67A-UD3R-B3
  dmi.sys.vendor: Gigabyte Technology Co., Ltd.

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