[OpenAFS] Re: Change IP of my AFS DB Server

Andrew Deason adeason@sinenomine.net
Fri, 11 Oct 2013 10:27:35 -0500

On Fri, 11 Oct 2013 12:10:34 +0200
Jean-Marc Choulet <jm130794@gmail.com> wrote:

> We have two AFS database servers with IP addresses and

Just in case you don't know, it's usually recommended to have at least 3
dbservers if you have more than 1. Having 3 dbservers is the minimum
number of sites so that you can operate will full functionality if any
one machine goes down. With only two servers, if your site
goes down, you won't be able to make changes to the databsases.

It's not a big deal or anything, just mentioning it in passing.

> Can we change IP addresses of these servers to a and b
> without problems ?

If you don't care about a little downtime, then yes, certainly. The
simplest way to do that is to bring down the servers, change the
server-side CellServDB to point at the new addresses, update all of the
clients, and bring up the servers with the new IP addresses. If you have
the old IPs referenced anywhere else, like in NetInfo/NetRestrict files
or in IP ACLs or something, you'd of course want to change those, too.

If it takes a long time to move the machines to IPs a and b, and you
want things to stay available, the above won't work, since the dbservers
will both be down while moving. Keeping the cell at least somewhat
available during such a move is more involved, but also possible.

> We are going to update all ours client stations of course.

Talking specifically about Unix clients:

Note that a client must be restarted to notice changes in the client
CellServDB. If you want to notify a running client of changes without
restarting it, you can run the 'fs newcell' command to tell the client
about the new dbserver info.

Andrew Deason