Re: initramfs broken on Jessie upgrade

[Bernhard Schmidt <berni@birkenwald.de>]

Bernhard Schmidt <berni@birkenwald.de> wrote:

> This is reproducible. To fix it it is enough to boot into the Wheezy
> kernel (even with init=/bin/sh), then reboot. It apparently does
> something to the root-fs (fsck?) which allows the Jessie kernel to boot.

Ben Hutchings had the right idea in Bug#783620.

Apparently the reboot leaves the filesystem in an unclean state. The new
initramfs is written in the journal, but not on-disk yet. Grub2 doesn't
read the journal, so it finds a corrupted initramfs. A boot with the old
kernel replays the log and the initrd can be read.

It is still unclear why the reboot is unclean at all. A sync before
reboot should help.

Bernhard