Bug#783620: initramfs-tools: initramfs broken on first boot into Jessie, "Unable to mount root fs on unknown-block(0, 0)"

[Bernhard Schmidt <berni@birkenwald.de>]

Hi maximilian,

>> [ copied from debian-user again ]
>>
>> ---
>> Got another system with the symptoms and managed to get a snapshot.
>>
>> It is really extremely weird. The kernel output is
>>
>> List of all partitions:
>> No filesystem could mount root, tried:
>> Kernel panic - not syncing: VFS: Unable to mount root fs on
>> unknown-block(0,0)
>>
>> 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.
>>
>> I have asked our Windows guys to make a screencast, it is uploaded here.
>>
>> http://users.birkenwald.de/~berni/volatile/783620.mkv
>>
>> We still have the snapshot available, if you have an idea please drop me
>> a note.
> 
> this means linux didn't get the initramfs passed by the bootloader.
> 
> In the old days this happened when lilo was not run, these days it could
> be some grub modules out of sync (very wild guess).
> did you try before botting into that image to run install-grub in it?

I don't have access to the snapshot until Monday, but I don't think it
will help. As you can see in the video a simple fsck/mount in initrd in
the old kernel is enough, and grub isn't touched there.

But I'll test on Monday to be sure.

Bernhard