[OpenAFS] Upgrading to newer OpenAFS procedure docs

[Benjamin Kaduk]

On Tue, Nov 27, 2018 at 12:38:16PM -0500, Susan Litzinger wrote:
> We are in the process of updating from an older version of OpenAFS,
> 1.4.14,  to a more recent version, 1.6.16.
> 
> The new 1.6.16 servers have been added to our current cell and we are
> moving the volumes from the older servers to the new ones.  We know that we
> have to move the various servers, including the VL Server,  and root.cell
> volume from the old servers to the new ones before being able to shut off
> the old servers. I'm trying to find documentation that describes how to do
> that.

The main obstacle is usually just the running database servers, including
both VL server and PT server (and also potentially a few others if in use
at your site, for the buserver, updateserver, etc.)  AFAIK root.cell does
not need to be hosted on a fileserver colocated with a dbserver (but is
just conventionally done so during normal operation for maximum
resiliency).

A key question is whether the dbservers will be getting new IP addresses as
part of this upgrade -- that requires a somewhat more complicated
procedure, whereas if the same IP addresses are used it's pretty
straightforward to just cycle machines in/out of active service.
Other factors that come into play is whether all clients are known and/or
under the control of central administrators, so that whether they are using
AFSDB or SRV records or a static CellServDB to locate dbservers can be
known.

> Has anyone done this recently?  Is there any documentation that describes
> the proper sequence?

The situation tends to be fairly customized for each site (and is not a
terribly common operation), so I don't know of any formal documentation.
The thread starting at
https://lists.openafs.org/pipermail/openafs-info/2017-January/042007.html
is probably the most recent discussion (n.b. the TLS certificate for that
site recently expired so you'll have to click through a cert warning at the
moment; other mail-archive sites may have the content as well, for the
thread subject "procedure for changing database server IP address").

-Ben