[Bug 672177] Re: libc6 upgrade causes umount to fail on shutdown because init cannot be restarted

[ingo]

Hi Clint,

me just came up an idea how we could make this bug hunting more
systematic and thoroughly. Up to now we just found some conditions in
which shutdown process fails (sshd and portmap). Who tells us that there
aren't more daemons which get hardly killed upon shutdown/reboot?

So, if for tracing we get a patched '/etc/init.d/umountroot' which does
following:

on shutdown when the messages
    init: Re-executing /sbin/init
    mount: / is busy
are issued it indicates that / is not yet umounted. So one could collect the open files (lsof) and write the information to disk. Then wait 5 sec.? untuil the filesystem has commited the journal to disk, try umount again and, if regular umount fails again just do *not* hard restet, but keep system in that state (user can do a cold reboot/shutdown manually).

Upon next boot-up the content of the saved processes could be read out
and attached to this bug report.

This way it should be possible to also detect other daemons not so
commonly used, which need their start/stop scrips to be fixed. Re-
installing libc6 appears to be a very sensitive trigger to make teses
oddities visible.

-- 
You received this bug notification because you are a member of Ubuntu
Server Team, which is a direct subscriber.
https://bugs.launchpad.net/bugs/672177

Title:
  libc6 upgrade causes umount to fail on shutdown because init cannot be
  restarted