[Linux-cluster] Strange error returned by openais

[Christine Caulfield]

On 03/03/10 09:02, carlopmart wrote:
> martijn at tenheuvel.net wrote:
>>> Hi all,
>>>
>>> I am trying to setup a rh5.4 cluster with only two nodes, but I can't.
>>> Under
>>> /var/log/messages I can see a lot of errors like these:
>>>
>>> These nodes have two network interfaces, one on the same network for
>>> cluster
>>> operation and another on different subnet. Like this:
>>>
>>> Node01: 172.16.1.1 (eth0) and 192.168.35.1 (eth1)
>>> Node02: 172.16.1.2 (eth0) and 172.26.50.1 (eth1)
>>>
>>> Default gateways point to 192.168.35.20 in node01 and on node02 to
>>> 172.26.50.30
>>> ... maybe this is the problem??
>>>
>>> I have put ip routing rules on both nodes but problem continues ... How
>>> can I fix
>>> this??
>>
>> I've had exactly the same errors, and eventually found what was wrong.
>> The problem seems to be the vlans, switches which block the multicast
>> traffic. For now I'm using a crosscable.
>>
>> So, check with the network engineers, they should be able to assist you,
>> but you can convince them they're blocking you using the crosscable.
>>
>> regards,
>> Martijn
>>
>>
>>
>
> Maybe you are right Martijn. I have copied manually cluster.conf from
> node02 to node01 and all works ok (node01 joins to cluster). But If
> mutlicast is the problem, why node01 joins to cluster if cluster.conf it
> is at same version than on node02??
>
> My problem only occurs when cluster.conf version is different between
> nodes ...


Well, that's exactly your problem! cman expects the cluster.conf to be 
the same version on all nodes. ccsd is meant to synchronise these in 
RHEL5 but it has problems with a two node cluster where quorum cannot be 
established.

What you need to do is either use two_node="1" mode in cluster.conf or 
use a quorum disk to maintain quorum while a single node is up.

Chrissie