[Pacemaker] communication channels howto

Dan Frincu dfrincu at streamwide.ro
Thu Aug 26 11:38:57 EDT 2010

In OpenAIS for example, in /etc/ais/openais.conf you have a directive 
called interface. In this directive you specify a ringnumber, 
bindnetaddr, mcastaddr and mcastport. Configuring 2 communication 
channels means using adding rrp_mode: passive, ringnumber 0 and 
ringnumber 1, two interface directives in which you use different 
bindnetaddr IP addresses (ex: and, or whatever IP's 
you use, but preferably each IP address should be assigned to a 
different network interface), two different mcastaddr multicast groups 
(or mcastport, but I'd recommed different mcastaddr's in the range of 

The principle behind it is if one communication channel (network card, 
IP address connectivity, multicast group/port) fails, the other one is 
still there for redundancy. I see this similar to the way ring network 
topologies work, without the token.


p.s.: Andrew, nice to have you back, to paraphrase a famous quote "Mr. 
Anderson. Welcome back, we missed you."

lxnf98mm at comcast.net wrote:
> The DRBD manual says
> It is absolutely vital to configure at least two independent OpenAIS 
> communication channels for this functionality to work correctly.
> My Google'n has not yielded any results in the how to do this department
> I have DRBD configured and working properly with one channel
> Where can I find info to add a second channel
> Richard
> _______________________________________________
> Pacemaker mailing list: Pacemaker at oss.clusterlabs.org
> http://oss.clusterlabs.org/mailman/listinfo/pacemaker
> Project Home: http://www.clusterlabs.org
> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
> Bugs: 
> http://developerbugs.linux-foundation.org/enter_bug.cgi?product=Pacemaker

Systems Engineer
Streamwide Romania

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