On Tue, 11 Jul 1995, Lyle Seaman wrote:
>
> As you say, one must configure multi-homed database servers very
> carefully. We have heard of a couple of cases where multi-homed
> database servers, though apparently carefully configured, developed
> problems with establishing quorum. It is possible that the problems
> are operating system-dependent.
We are currently running 2 (soon 3) multi-homed file servers (each with 2
ATM interfaces), one of which is also the DB server. (We tried with 3 DB
servers with an earlier network config (FDDI), but had unacceptably long
(> 5 minutes) periods of non-availability every time we stopped one of the
DB servers.) Should I interpret your statement to mean that we should NOT
try using 3 DB servers in the current config? Would AIX be one of the
operating systems which have shown problems with multi-homed servers?
> We can certainly revise the protocol
> to eliminate the risk of multi-homed database servers, but I believe
> that supporting multi-homed file servers is a higher priority.
> Because of the difficulty and uncertainty involved, we are trying to
> discourage people from using multi-homed database servers until a
> simple solution can be devised.
Please increase the priority of multi-homed database servers. Otherwise,
we'd be obliged to set up machines which are ONLY DB servers and that
costs money. We need the multi-homing on the file servers because even ATM
is finite, so we have one towards our tape servers (accessing 6 Storagetek
ACLs) and one towards the batch clients.
>
> What the manual is trying to say is that if you are having quorum
> problems with multi-homed database servers and you call in for
> support, you probably won't get a lot of help other than a pointer
> to udebug and a reminder that multihomed db servers are unsupported.
> But if you have something set up that works for you, we're not going
> to send out a kneecapper and repo your software, no. Good luck.
As I said, we have had problems with quorums. So I guess the message is
clear.
My message is still: PLEASE increase the priority of having multi-home DB
servers.
John
--------------------------------------------------------------
John O'Neall e-mail: [EMAIL PROTECTED]
Responsable Systeme
Centre de Calcul de l'IN2P3 phone: (33) 78 93 08 80
Villeurbanne, France fax: (33) 78 94 30 54
