[OpenAFS] Transitioning from IBM Transarc to OpenAFS Help

[John Harris]

Greetings OpenAFS Community,

We are *finally* going to transition our production AFS cells from IBM 
Transarc to the OpenAFS code base.
I have lots of questions and discussion points and am not sure if this 
is the appropriate forum to do it in, so I'd first like pointers on 
where to place it.  I also hope to contact other companies/universities 
that have made the transition to get some pointers.

Unfortunately, we are running on majorly patched IBM code; meaning the 
code that branched to OpenAFS a number of years ago has been patched 
several times on proprietary needs of IBM's customers.  We aren't 
running anything different than their *latest* release version and I've 
gathered enough info to know that the problems they patched have already 
been addressed in OpenAFS, but I assume there are major differences now 
even in the kernel module...?

Here, we are debating about a couple of ways to transition:

1) The communications-type folks, you know, the ones who don't actually 
do any of the work, want to keep the same cell name and just do a 
one-time massive integration come cut-over day.  They hope to mix and 
match IBM servers (database and fileservers) and OpenAFS servers (ie: 
just added OpenAFS servers and rotate the IBM ones out).  To me, this 
just screams of database corruption and problems; the technical side of 
our house is really against this (we have enough problems with running 
on one code-base) for various reasons, but it would be quickest way.  
Before I go testing this for weeks on end, does this community have any 
opinions on it.

2) The technical-type folks here want to start over with a new cell name 
so we can slowly transition our production clients over one at a time, 
have the old cell running for easy cut-back, take the time in the new 
cell to design the layout and permission scheme the correct way (like no 
individuals on ACLs, etc.), etc.

This is slower but safer and easier in my opinion.  We have lots to do, 
like transitioning from the afs4-krb database and K5, moving to newer 
hardware, etc.

I'd really like some feedback, either in the appropriate forum or 
personally, on experiences or thoughts.  There isn't a lot publicly out 
there on a big transition like this.

Sincerely,

John Harris
University of California, Davis