[OpenAFS] Re: [OpenAFS-devel] 1.6 and post-1.6 OpenAFS branch management and schedule

Rainer Toebbicke rtb@pclella.cern.ch
Thu, 17 Jun 2010 09:30:55 +0200

Russ Allbery schrieb:

> I'm aware of the following (largish) things that we want to deprecate or
> remove:
> * --enable-fast-restart and --enable-bitmap-later are earlier attempts to
>   solve the problem that is solved in a more complete way by demand
>   attach.  Demand attach will be available in 1.6 but not enabled by
>   default.  These two options will conflict with demand-attach; in other
>   words, you won't be able to enable either of them and demand attach at
>   the same time.
>   At the point at which we make demand attach the default, rather than
>   optional behavior, I believe we should remove the code for these two
>   flags.  I think that should be for either 1.10 or 2.0 based on
>   experience with running 1.6 in production.  In the meantime, please be
>   aware that most of the developers don't build with those flags by
>   default and the code is not heavily tested.

I'm concerned about removing the code for fast-restart and bitmap-later just 
because DAFS becomes the default.

We've been running with our own "on-demand-attach" since 5-6 years in 1.2 and 
1.4 with perfect satisfaction, and given its size and impact on the code I'd 
rather wait until DAFS gets a decent share of debugging before considering to 
move to it.

On the other hand, salvaging a complete file server just because of a crash is 
not an option, and removing anything that's required for it, be it 
fast-restart, bitmap-later or whatever, becomes a show-stopper!

Rainer Toebbicke
European Laboratory for Particle Physics(CERN) - Geneva, Switzerland
Phone: +41 22 767 8985       Fax: +41 22 767 7155