[OpenAFS-devel] NAT Patch and bugfix for vlserver

[Jeffrey Hutzelman]

On Wednesday, April 26, 2006 09:30:59 PM +0200 Tommie Gannert 
<d00-tga@d.kth.se> wrote:

>> Unfortunately, you can't get 'vos listvldb' to directly show you server
>> UUID's or more than one address per server.  However, any given address
>> can only be assigned to one server, so you can take the server names or
>> addresses reported by 'vos listvldb' and feed them to 'vos listaddrs' to
>> find out the UUID and/or other addresses assigned to that server.
>>
>
> Makes sense.
>
> Is an extension of listvldb a possibility? (For
> consistency, deprecating the old RPCs.)

I don't see why listvldb could not be made to use the new interfaces.

> So, now my question is... Is buserver in use? Do people use tapes or
> can it be safely converted to file based storage?

I don't use it, but recent mailing list traffic suggests that some people 
do, and that people are doing backup to tape.  File-based storage is nice 
for handling recent-timeframe restore requests, but doesn't do so well with 
things like "get me back this file I deleted 5 years ago", or with some 
kinds of disaster recovery.


>> > I'm not sure if the clients are better off making the decision,
>> > though. If they are behind NAT with the same subnet as the server,
>> > things will get messy. The idea of using common address bits means
>> > it will resort to global address space pretty easily. However, it's
>> > a hack, yes.
>>
>> Well, it's got to resort to a global address if it's not on the same
>> private network as the server.  However, since the vlserver never gets to
>> see the client's private address, it's not really in a position to make
>> the right decision.
>>
>
> The Thesis:
>
>   The address which the server sees, is in the same subnet the server
>   is on, as seen from the client.

Suppose you have a server and client that are behind the same NAT, and so 
share private address space.  But at least one vlserver is outside the NAT, 
and has a routable address.  In that configuration, that vlserver will not 
know the client and server share a private subnet.

-- Jeffrey T. Hutzelman (N3NHS) <jhutz+@cmu.edu>
   Sr. Research Systems Programmer
   School of Computer Science - Research Computing Facility
   Carnegie Mellon University - Pittsburgh, PA