It's been a couple of months but I finally got around to revisit this bug. I had this happen reliably on 2 laptops, both updated from previous versions of Ubuntu.
On one of these "plymouthd" really seemed to be the culprit (see my own comment #22 ). I found out that the memory mapped region was actually opened in plymouth's X11 frame renderer (through libdconfsettings.so which seems to be part of gio). Uninstalling the X11 renderer ("apt-get remove plymouth-x11") helped on this laptop. But this package wasn't even installed on the other laptop. Here, it was an instance of git-daemon (a runit service) which was still running causing svlogd to still keep a log file open. After uninstalling ("apt- get remove git-daemon-run") the busy mount at first seemed to have disappeared on this machine, too. But yesterday I had another busy mount caused by modem-manager still running which caused init to keep a log file handle open on "/var/log/upstart/modemmanager.log". So, in conclusion this is probably more of a meta-issue concerning a wider range of packages which would explain why the mentioned workarounds do not fix this issue reliably for everyone. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1019347 Title: A message: "mount: / is busy" appears every time shutting down or rebooting. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/plymouth/+bug/1019347/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs