[OpenAFS-devel] Re: Thinking about 1.6

[Andrew Deason]

On Thu, 17 Dec 2009 00:31:16 +0000
Simon Wilkinson <sxw@inf.ed.ac.uk> wrote:

> On 17 Dec 2009, at 00:25, Derrick Brashear wrote:
> > Well, the bosserver could attempt to stat() salvageserver and error
> > instead of trying an "fs" configuration if it exists.

Considering our location for the salvageserver binary is at best a
guess, I think that may have too high a chance for false-positives and
refusing to start.

And there's also the case if you just overwrite the binaries with
non-DAFS binaries to roll back, that obviously won't work.

> Or we could change the name of the binary for the dafs fileserver.  
> That would ensure that the old 'fs' configuration would fail, rather  
> than doing something unintended.

Possible problems are that if the old binaries are still there, you
effectively fail to upgrade; not a bad side effect, but it's harmless
enough that the user may never know they're not running the new version
they thought they installed.

That also potentially 'breaks' existing DAFS installations in the same
way. Still not horrible, but again, the user may never know.

Right now I'm leaning towards not allowing the 'fs' configuration when
DAFS is enabled unless you pass a switch, or somehow explicitly mark it
in some other way, as it's a very uncommon case. That would make the
configuration invalid with pre-1.6 bosservers, though... but at least it
would fail obviously.

-- 
Andrew Deason
adeason@sinenomine.net