Re: feature request - prevent user stupidity (eg mine)

[Mark Williamson <mark.williamson@cl.cam.ac.uk>]

> >The nice thing about the hotplug scripts is that they Just Work for
> >dynamically adding devices.  Unless I've misread Kan's code, it won't
> > catch a user accidentally adding a duplicate blkdev to a running domain,
> > which is a shame.
>
> Could you teach me a blkdev definition or a adding blkdev operation that
> my code cannot catch that you think of?  I'd like to test them by my code.

I was thinking your code didn't get run at block-attach, but later on I 
started to think maybe it was :-)  Is it? ;-)

> >We should try to figure out if this can be added reliably to the blkdev
> >hotplug scripts.  If not, maybe we should put all the checking into Xend,
> >with hooks to validate added devices.
>
> I'd like to check a duplicate blkdev for both xm new command and xm create
> command, so that I added the checking into xend(XendConfig.py).
> If the duplicate blkdev is notified of by xm start command, I think that
> it is late.

Ah, I hadn't thought about xm new.  Well, in that case it sounds fairly 
reasonable to add to Xend, and your code looked OK to me.  Given that, I'd 
have no objections to your patch going in.  Might save me from PBKAC (Problem 
Between Keyboard And Chair) one day :-)

Cheers,
Mark

-- 
Dave: Just a question. What use is a unicyle with no seat?  And no pedals!
Mark: To answer a question with a question: What use is a skateboard?
Dave: Skateboards have wheels.
Mark: My wheel has a wheel!