[OpenAFS] Migration from Transarc to OpenAFS

Joe Di Lellio joed@ucsc.edu
Mon, 7 Aug 2006 17:03:35 -0700 (PDT)

Roel & I are working on this here.

On Mon, 7 Aug 2006, Jeffrey Hutzelman wrote:

> On Thursday, August 03, 2006 11:53:14 AM -0700 Roel Flora <rflora@ucsc.edu>
> wrote:
> >
> > I was wondering if anyone has done a migration from Transarc to OpenAFS
> > recently and can provide some suggestions on how to do the migration
> > smoothly. We have a large number of existing users and around 1 Terabyte
> > of data to move. I expect that there will be some downtime that is
> > necessary while we are doing the migration, but we would like to minimize
> > the downtime  if possible.
> You should not need more than a few minutes of downtime, to allow your
> database servers to be upgraded.  Even that can mostly be avoided, if you
> are careful enough and if you're not upgrading from something too old.

So, what qualifies as 'too old'?  We do have an 'older' setup at UCSC,
but it's not ancient.  Set up ~2001, version 3.6 (looks like).  As I
understand it, the issue at hand was DB format; see previous post about
how TransARC wanted to be able to change it, but that OpenAFS hasn't
changed it since the launch.

> > So far, we have installed and setup OpenAFS servers using
> > the same cellname as the old Transarc servers but they are independent
> > of each other (using different ip addresses and not talking to each
> > other).
> Don't do that.  Forget about the "new" cell, and instead set up new servers
> in the existing cell.  Then you just move volumes to them, and your users
> notice no downtime.  One of AFS's most important features is that even
> major upgrades like this can be done without user-visible downtime; take
> advantage of that.

So barring the potential problem above, I can run OpenAFS systems - both
DB and fileservers - mixed with TransARC?  And then just 'retire' the old
TransARC boxes once I've brought their upgrades into the cell?

This would make our lives rather easy.  I'm assuming enough folks have
done this, as there can't be that many TransARC installs out there (er,

Regardless, thanks for the info.

It ain't what you don't know that gets you into trouble.  It's what you
know for sure that just ain't so.		-- Mark Twain