Comment 10 for bug 1103187

New progression in confirming, that "grub-install /dev/sda" writes block information into boot area, while the content of these block are refreshed much later, latest at the next mounting of the XFS root filesystem.

The "dpkg-reconfigure grub-pc" contains first "grub-install /dev/sda" and second "update-grub".

My separated experinces shows, that the second, "update-grub" makes no reboot problem, while "grub-install /dev/sda" is guaranteed to cause reboot fail.

I found an interesting new error, occuring wery late during the boot process, namely I could already see the graphical works space, when a small window popped up informing me, that

        Sorry, Ubuntu 12.10 experienced an internal error.

There was a facility to automatically send a report of it, I sent it.

Now the real progress is, that I found that the OTHER PROBLEMS described in the very first post

        "booting the new kernel hangs at the missing initial ram disk"

now knowing much more about the incoherency problem, so now it is clear, that the initial ram disk FAILS TO BE MISSING, instead, due to the incoherency problems, the boot process can't see the new initial ram disk of the new kernel!

Just after the previous post, I received the new kernel 3.5.0-23, this is the 6. kernel update since the release of 12.10. As a surprise, this time there was NO reboot problem. Hence I decided to remove the previous kernel, the 3.5.0-22, and immediately I got reboot problem, but slighly different from the previous ones:

namely I got NORMAL grub prompt, but in turn of it, the linux.mod was not loadable in spite of the fact, that it was listable,

and the most instructive fact was, that I could reach the DELETED kernel, ramdisk etc!, while the new ramdisk was missing, while at the last boot I could boot it!

This means, that when dpkg purged the previous kernel, then the file system journaled what to do, but did not eventually do it on the block level before the reboot.

Now I see, that the diverse kind of problems in the last 2 1/2 months were NOT diverse, but only this incoherency problem.

As a result, sometimes I got normal grub, but initrd was missing, or it was not missing, but the grub menu was missing, etc. Other times the grub stoped at it's rescue mode due to the apparent inaccessibility of normal.mod, etc. These caused the impression of having diverse problems instead of a single one.