Unmounted OS are not found

Sadly, each time installing packages that make grub menu rebuilt, the previous good grub menu is lost if all the OS partitions are not mounted. What is expected: os-prober might be able to scan and find all the OS installed on all devices, mounted or not.

New output with latest Jan 20th packages updates: some uuid packages and grub rc1:

- previous grub menu complet (was built bt previouly mounted all the os partitions
- apply the updates (uuids & grub rc1) with only natty partition active, the others are not mounted and still a minimal fstab
- the result is:
 a) install grub rc1 with the dev default settings
 b) when installing rc1 i see (dialog box details) that it only find natty and maverick (same sata disk, both 32 bits) but not lucid (i386) on an other disk (this one is pata)
 c) on reboot, the grub menu effectively miss lucid entry

Can you try mounting the filesystem in question, unmounting it straight away, and then running os-prober? If this works around the problem (I'm not suggesting it as a permanent solution), then this is the same as bug 683355.

hi Colin,

as described into #3 above (previously mounted OS) can built a complete grub menu, there is no problem on that side.

After watching bug 683355 & bug 672177, i think you can consider this bug is very close and the key-words here are "uncleanly-unmounted filesystems" too because:
 "reboot" never work: the system is unable to completly stop: the session & X are closed but the system continue to run,
 but if i choose to directly "stop" and exit, the system seems to close normaly, but on next boot it always fail, so again: the " uncleanly-unmounted" seem to be the problem.

As suggested, i've reinstalled libc6 & called shutdown -r, but everything is clean: no broken inode.

Thinking about "uncleanly-unmounted" issue, i wonder if we can say that a (few) still running process lock the situation and make the shutdown unclean ?
If an unkilled process have to be blamed, how to know about it and force to kill it to get a clean unmount ? (maybe something related to apparmor, or else)

If mounting the partition helps, then this is bug 683355 so I'll mark this as a duplicate. Thanks.