[Linux-HA] Behavior of heartbeat when network is down

[Patrick Begou]

I'm new on this list. I'm using/trying to administrate a Debian HA 
system (2 nodes) for more than one year but it isn't me who build it. 
So, I'm still a newbie.

I've spent a lot of time in the documentation found on linux-ha.org to 
adjust the config and solve minor problems but there is still a problem 
with my config and I've no idea where to start.

Question:
Is it possible, when the 2 nodes are unable to ping the "ping node" to 
tell heartbeat to wait and do nothing ? My 2 nodes are connected with a 
direct ethernet connection and can communicate with the other ethernet 
device.

Details of the problem:
I've an active/active config: 2 server runing drbd, heartbeat, mon...
First one for NFS and LDAP
Second one for DNS, BIND, SMTP

Each server can run the 2 pools of services if the other node fails.

All works fine except... if the global network goes down! Yesterday a 
student plugs the same ethernet cable into two ethernet connector of the 
same switch :-(

The 2 servers were not able to ping anymore the "ping host" and:
- heartbeat stops services on server one (because it could not see the 
ping host I think).
- server two do not takeover the services but keeps its own services
- when network was again operational the stopped services where not 
restarted on any of the two servers (drbd was secondary/secondary and 
filesystem was not mounted)
- I was unable to run a heartbeat restart command on any node (command 
freeze for a long time and I have to hit [ctrl][C].
etc...

I solved the problem by halting the 2 nodes ("hard stop") and starting 
them again. But I don't like this method!


Thanks for your advices.

Patrick

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