Re: Kernel crash during heavy disk access

> Date: Tue, 9 Jul 2013 18:29:01 -0700
> Subject: Re: Kernel crash during heavy disk access
> From: Adrian Chadd <adrian_at_freebsd.org>
> To: Benjamin Kaduk <bjk_at_freebsd.org>, Jeff Roberson <jeff_at_freebsd.org>,
>         Kirk McKusick <mckusick_at_mckusick.com>
> Cc: Eric Camachat <eric.camachat_at_gmail.com>, current_at_freebsd.org
> 
> Well, best to tell kirk and jeffr.
> 
> Jeffr wrote the journaling stuff.
> 
> .. but I thought they knew there's still problems?
> 
> -adrian

Jeff has fixed all the journaling issues for which we have some way
of reproducing them. We do still have some reports that there are
"problems" but only a vague description and nothing that we can use
to reproduce them on our systems.

One of the inherit characteristics of any type of journaling is that
once it thinks that it has fixed something, it never goes back and
checks it again later. So, if there is some inconsistency that gets
into your filesystem through media error or an earlier journaling bug,
it will stay there and continue to plague you until a full fsck is
run to clean it up. So, if you are getting filesystem related crashes,
the first thing you should do is a full (fsck -f) check to make sure
that you are starting from a clean state. After that, if you find that
the journaling is not keeping it consistent, please send Jeff and me
a report of what you are doing, what problems it creates, and most
importantly transcript of a run of `fsck_ffs -d' first using the 
journal and then a second time with a full check (fsck_ffs -f -d)
so that we can try to analyse what is going wrong. Note that you
need to run fsck_ffs explicitly because the fsck front end will not
pass the -d (debug output) flag through to fsck_ffs.

	Kirk McKusick

> On 9 July 2013 17:48, Benjamin Kaduk <bjk_at_freebsd.org> wrote:
>> On Tue, 9 Jul 2013, Adrian Chadd wrote:
>>
>>> On 9 July 2013 09:24, Eric Camachat <eric.camachat_at_gmail.com> wrote:
>>>>
>>>> On Mon, 2013-07-08 at 23:05 -0700, Adrian Chadd wrote:
>>>>>
>>>>> Hi,
>>>>>
>>>>> Try doing a full, non-journal fsck.
>>>>>
>>>>> -adrian
>>>>
>>>>
>>>> Thank you, it fixed the problem!
>>>> Does it mean journal didn't work?
>>>
>>>
>>> Yup :(
>>
>>
>> So, you are going to tell Kirk about it?
>>
>> -Ben