[231] in Zephyr Mailing List
Re: Changing IP address of zephyr server
daemon@ATHENA.MIT.EDU (Derek Atkins)
Mon Nov 25 17:19:05 1996
To: "Bob Oesterlin" <oester@VNET.IBM.COM>
Cc: zephyr@MIT.EDU
From: Derek Atkins <warlord@charon.MIT.EDU>
Date: 25 Nov 1996 17:15:18 -0500
In-Reply-To: Bob Oesterlin's message of Thu, 21 Nov 1996 19:24:37 -0600 (CST)
Bob Oesterlin <oester@VNET.IBM.COM> writes:
>
> I want to change the IP address of one of our zephyr servers - what's
> the best procedure?
I'm not sure there is really a "best procedure". Assuming you want
data to remain online through the upgrade, you need to be sure that a
braindump can happen at all times...
> I was thinking of taking down one of the existing servers, bringing up
> it up again under it's new address so that it can find the other server,
> then recycling the other server.
The problem is that *both* servers need to know about each other for
the braindump to work. What would happen, most likely, in this case
is that the new server would try to contact the old server for a
braindump but would be refused. I haven't looked at the braindump
code, so I'm not 100% sure this check is done, but I think it is (or
should be ;)
What you should probably do is bring down the server that is *not*
changing address, add the new address to the list, then bring it up
and wait for braindump. Then you can change the address on the other
server and bring it up, again waiting for a braindump. Then at your
leisure you can remove the old ip address from the first server.
> What about the clients... do I have to recycle zhm or will "zctl
> new_server" do it?
ZHM will need to be restarted to get the new list of zephyr servers.
You never said whether you were using Hesiod for server lists. If so,
then you just need to reset zhm... I think a HUP *might* get it to
re-query hesiod, but I'm not sure if that code ever made it back into
the release. If so, then a HUP will be enough. Otherwise you need to
restart zhm to get it to see the new server (and stop trying to old
one).
-derek
