[DRBD-user] Re: Suggestion to prevent split brain situation

[Florian Haas]

Bas,

On Monday 03 December 2007 11:57:11 Bas van Schaik wrote:
> Florian Haas wrote:
> >> Thanks for the clear explanations. I think it needs to be said that I'm
> >> probably using DRBD in a less professional setup than you guys are.
> >> Setting up redundant network connections is way beyond my possibilities,
> >> it simply isn't worth the money and effort. The same holds for the
> >> Heartbeat setup, but maybe I'll take a better look at that later.
> >
> > I find it doubtful that it's "way beyond your possibilities" to use that
> > second on-board NIC that your servers presumably have, and a crossover
> > cable, for dedicated DRBD replication and a second Heartbeat link.
>
> They do not have a second on-board NIC, but I'll consider upgrading them.
>
> > However if you're not using Heartbeat, or any cluster manager for that
> > matter, at all, then there isn't much that will keep you from running
> > into split brain eventually.
>
> That is exactly why I made my suggestions the other day. But you have
> been clear about this: I should use DRBD in a more professional way, or
> I shouldn't use it at all.

It's a little harsh the way you put that. :-) This doesn't have much to do 
with being more or less professional. But please understand that for the 
problem you mentioned, a solution already exists in the form of dopd. And 
please also understand that your alternative suggestion of DRBD refusing to 
become Primary when disconnected is diametrically opposed to DRBD's primary 
purpose, namely, to provide storage capability in an HA cluster capable of 
automatic fail over. And DRBD won't get "fixed" to suit your scenario when 
that "fix" would break the vast majority of DRBD-based clusters out there.

Hope this makes my point clearer. Apologies if I sounded rude earlier.

Cheers,
Florian

-- 
: Florian G. Haas 
: LINBIT Information Technologies GmbH
: Vivenotgasse 48, A-1120 Vienna, Austria