In Quantal, the root filesystem is not cleanly unmounted at shutdown or reboot
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
network-manager (Ubuntu) |
Incomplete
|
Medium
|
Unassigned |
Bug Description
Ever since some update in the Quantal pre-releases, having dnsmasq-base installed will cause the root filesystem to not be properly unmounted on shutdown and reboot. In case the Plymouth splash screen is disabled, the message 'mount: / is busy' will be shown, but otherwise the user will not even be aware of this problem.
After rebooting, the root filesystem needs recovery, as shown in dmesg:
kevin@vbox-
[ 1.022746] EXT4-fs (sda2): INFO: recovery required on readonly filesystem
[ 1.022750] EXT4-fs (sda2): write access will be enabled during recovery
[ 1.248294] EXT4-fs (sda2): recovery complete
[ 1.248661] EXT4-fs (sda2): mounted filesystem with ordered data mode. Opts: (null)
[ 1.456315] EXT4-fs (sda2): re-mounted. Opts: errors=remount-ro
Yet again, the user will not be aware of this until it is too late. The only way to avoid this from happening (or at least what I've found) is running 'sudo apt-get purge dnsmasq-base'. Sadly, this also removes network-manager and network-
Another problem that might be related is that having an active connection with the Network Manager prior to shutting down or rebooting, will cause the process to hang for a few seconds, after which the message about / being busy is shown. Stopping the network service (sudo service networking stop) will solve the hanging, but not the unclean unmount. So far, only purging dnsmasq-base seems to do that, which obviously also solves the other problem, as Network Manager will then also be removed.
Although I haven't experienced it yet, this could cause potential data loss; especially for users without a seperate /home partition.
ProblemType: Bug
ApportVersion: 2.5.3-0ubuntu1
Architecture: amd64
Date: Sun Sep 30 12:49:24 2012
DistroRelease: Ubuntu 12.10
Package: dnsmasq-base 2.63-1ubuntu1
PackageArchitec
ProcVersionSign
SourcePackage: dnsmasq
Tags: quantal
Uname: Linux 3.5.0-16-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
I've tested some more tonight, and I can reproduce this on everything I used. Both Ubuntu 12.10 and Xubuntu 12.10 stock, unmodified, clean installs show this behaviour; both in VirtualBox and on my testing machine. Installing all the updates makes no difference. manager- gnome (which pulls in dnsmasq-base). That's when this bug starts to show up.
Also, doing a fully up-to-date netinstall works fine until I install network-
dnsmasq-base causes the 'mount: / is busy' message, which indicates an unclean unmount of the root filesystem (confirmed by fsck on the next boot), and network-manager seems to cause the long delay before actually shutting down. Obviously, purging dnsmasq-base solves both, as this will also remove network-manager.