ZFS on root booting broken somewhere after r270020

[Kimmo Paasiala]

> On 19.8.2014, at 10.46, Konstantin Belousov <kostikbel at gmail.com> wrote:
> 
> On Tue, Aug 19, 2014 at 10:32:08AM +0300, Kimmo Paasiala wrote:
>> 
>> On 19.8.2014, at 10.10, Konstantin Belousov <kostikbel at gmail.com> wrote:
>> 
>>> On Tue, Aug 19, 2014 at 07:40:46AM +0300, Kimmo Paasiala wrote:
>>>> 
>>>> On 18.8.2014, at 8.54, Kimmo Paasiala <kpaasial at icloud.com> wrote:
>>>> 
>>>>> 
>>>>> On 18.8.2014, at 2.32, Kimmo Paasiala <kpaasial at icloud.com> wrote:
>>>>> 
>>>>>> System is:
>>>>>> 
>>>>>> FreeBSD freebsd10.rdnzl.info 10.0-STABLE FreeBSD 10.0-STABLE #2 r270020: Fri Aug 15 20:38:59 EEST 2014     kimmo at buildstable10amd64.rdnzl.info:/usr/obj/usr/src/sys/GENERIC  amd64
>>>>>> 
>>>>>> This version still works fine. The one that didn?t work was r270097. The kernel boots but gets stuck at the line:
>>>>>> 
>>>>>> Trying to mount root from zfs:pool/ROOT/default []
>>>>>> 
>>>>>> I tried pressing enter at this point but got a panic, I don?t have a screenshot of the panic at the moment.
>>>>>> 
>>>>>> Could this problem be related the this commit? :
>>>>>> 
>>>>>> http://svnweb.freebsd.org/base?view=revision&sortby=rev&sortdir=down&revision=270095
>>>>>> 
>>>>>> -Kimmo
>>>>> 
>>>>> Trying to bisect this I backed to r270050 and that version still works. More to come.
>>>>> 
>>>>> -Kimmo
>>>> 
>>>> Version r270094 still works but commit r270095 definitely does break booting from ZFS on root on my system. The error message I see on the console is  ?Mounting from <the ZFS filesystem> failed with error 5? and I?m given the mountroot prompt. I don?t see the ZFS pool among the listed GEOM devices on the mountroot prompt.
>>>> 
>>>> Adding the committer of r270095 (kib@) to this discussion.
>>> 
>>> I have no idea about ZFS, but the fact that things, which are lower-level
>>> than ZFS filesystem itself are missing, suggests that the issue is unrelated.
>>> At the very least, start with providing the verbose boot dmesg for successful
>>> and failed boots.
>> 
>> This looks like to be unrelated to ZFS as you?re saying. I just remembered that I?m loading fuse.ko in my /boot/loader.conf. I commented that one out and what do you know? The system boots fine with the r270095 kernel.
>> 
>> Very very strange? 
> This probably indicates KBI mismatch.
> 
> Is your fuse.ko installed from the kernel build ?
> Still, I think the verbose dmesg is the start to look.
> 
>> 
>> Thanks for the input anyway,
>> 
>> -Kimmo
>> 
>> 
>> 
> 
> 

Hi it’s me again. Something that was committed in stable/10 after r271213 up to and including r271288 broke ZFS on Root booting in exactly the same way again. I know the problem is no longer related to extra kernel modules loaded in /boot/loader.conf because I’m loading only the required zfs.ko and opensolaris.ko modules. Also, the new vt(4) console that I’m using is not the culprit because the same thing happens with kern.vty set to “sc”.

-Kimmo