After talking with Mark Miltenberger, from Novell, it seems that the
recommended way to replace a NW51 server with an OES2/linux server is to:

1. prepare the tree using the first part of deployment manager
2. update SMS using tsa5up19.exe
3. install oes2/linux into same tree
4. prepare nss on new server
5. Yast volume migration
6. modify login scripts and user workstations to use the new server name
and ip
7. remove old server from tree

I'm a bit disappointed that I can't make the server migration invisible to
the users.

I'm stuck on step #5.
TSA500.NLM is loaded on the Netware server.
I'm getting an error when I try to use YAST volume migration.

Error: nbackup: Connection denied.
Error: nbackup: Error while reading from archive.