[Linux-cluster] RHEL6 HA addon

[Richard Allen]

Hi all

I notice in the Release Notes for RHEL6 that many changes have been made 
to the Cluster Suite (HA Addon) but I am unable to find any mention of 
how the new suite does heartbeat.
In previous versions the Cluster could only do heartbeats (node 
intercommunication) on one network link and for redundancy the only 
option was to use bonded network devices.
There was a way to add a second heartbeat using altnode directives in 
the XML config file but that always felt a bit hackish and was only 
limited to only one altnode, giving two heartbeat paths.

So I would like to ask how RHEL6 does this.  If I have nodes with 4 10Gb 
NIC's, one connected to an admin network, another to a Database network 
and one to the Application network and the last one connected directly 
to the other node with a crossover cable, can the cluster now use all 
possible paths to communicate to the other nodes or will one of those 
paths become a single point of failure in the cluster?

I'm used to using Clusters like HP's ServiceGuard where I can easily 
define which links to use as heartbeat.  It can even use a serial 
connection (in a two node cluster) as a additional heartbeat and I have 
always felt this is quite a big limitation in Red Hat's cluster suite up 
to RHEL6 atleast.

Thanks in advance
Richard.