[OpenAFS] A few questions now

[Ryan Underwood]

hi,

> > XFS or ReiserFS crashes the kernel on Linux if you try to start the client
> > with cache pointing to them.  I haven't tried JFS.
> 
> Good point. I don't know on that... 

However, it was probably a fallacy to attribute this directly to the journaling
capability of the filesystem.  I guess I should amend that by saying "Some
filesystems on Linux, all of which happen to also be journaling, crash afsd
when starting the client cache."

> > Hm, that's true; what about hiding special nodes from non-unix systems? ;)
> 
> major 31 minor 0 on HPUX is one of the systems disk drives
> 
> major 31 minor 0 on Linux is an interface to the MPU401 midi encoder on
> soundblaster audio cards.

Ok, device nodes are obviously a non-starter.

> Now, that shouldn't be an issue for a unix socket, or fifo. Those would
> be relatively safe to allow creation of, and should be portable to any
> platform that supports the concept of a fifo or named pipe.

I would like this capability.

> > similar.  However, even being able to run a fifo'ed program in AFS space
> > would be neat, and obviously the only workable solution if a multicast fifo
> > would be ugly.
> 
> Fifo's are purely local. Even on NFS. The idea of having networked fifos
> is just plain scary. 

hm, ok, I must be confusing some things.  I thought on NFS, you could write
to a fifo and read from it on another machine.  Now that I think about it,
that's a rather dumb thing to believe, since the fifo has no file data
associated with it; the data is just shuffled around in the kernel.

If it _were_ possible to implement a service in AFS that allowed network
client/server or multicast IPC through fifos in AFS space, that would just
be damn cool.  I'm not volunteering, though. :)

> Only user required user space code is afsd, and that's pretty small, and
> could probably be compacted down quite a bit if you got rid of all the
> configurability.

Interesting.  I wonder if we shouldn't distribute a stripped-down client
like this.  For "thin" clients, especially.

> > Hrm, but what if I'm not doing anything related to the machine at the time?
> > 
> 
> Has nothing to do with the machine you're on.

Sorry, by "the machine" I meant the fileserver that the volume is on.
Small network here. :)

> where the volume is, and 'vos status' on the server in question if you
> see a persistent busy volume message.

I will do that next time I notice the message.

> Just use "fs copyacl dir1 dir2".

Thanks.  I have a copy of Campbell's "Managing AFS", but I seem to
bury it under piles of crap on and around my desk.

-- 
Ryan Underwood, <nemesis at icequake.net>, icq=10317253