BTRFS: The Good, The Bad and The Ugly

[Josef Bacik]

On Thu, Jul 14, 2011 at 11:21 AM, JB <jb.1234abcd at gmail.com> wrote:
> Josef Bacik <josef <at> toxicpanda.com> writes:
>
>> ...
>> I've already said
>> that if it's not in good shape by Alpha the switch won't even be made,
>> so quit your bitching.
>>
>> Josef
>
> Josef,
> would it be possible, BEFORE (in case that) you decide to switch on before
> Alpha, to present some test suite results (a la Phoronix, etc) that would
> assure yourselves and Fedora testers/users of BTRFS fitness ?
>
> If it came from you it would have a special weight and a sign that you
> do no want to sell cats in a bag :-)
>
> I hope, that the community at large will parallel it with their own tests.
>

The problem is we test it regularly with lot's of artificial tests.
We all run xfstests for each patch, I have a bunch of ENOSPC tests
that I run and Chris does large stress tests before he sends pull
requests to Linus.  This thing is tested to death.  We are at the
point that it is pretty stable, which is why we're having this
conversation.  We've reached the point where we really need wider user
testing, because no amount of testing we do will ever be able to match
up to the crazy things users do.  For example I don't see these random
high latency issues that have been discussed in this thread with my
testing, so I'm going to have to figure out a way to make that happen
so I can try and fix it.  I would have never seen that in my own
testing.

So far the wider testing I've gotten has been good, basically we just
have a couple of key performance issues, VMs and random latency
spikes.  That's not too bad all things considered.  The VM thing I
think I can have fixed by 3.1, but the latency spikes thing is going
to take some looking into, and if I can't get that nailed down that
will be a big reason not to go with Btrfs as default.

But you have to remember a huge requirement is going to be having a
working fsck by Alpha, and that seems less and less likely every day,
so chances are we won't even make Alpha and I'll have to fill out one
of these annoying feature pages for F17.  Thanks,

Josef