[Gluster-users] Crossover cable: single point of failure?

[Daniel Manser]

 Dear community,

 I have a 2-node gluster cluster with one replicated volume shared to a 
 client via NFS. If the replication link (Ethernet crossover cable) 
 between the Gluster nodes breaks, I discovered that my whole storage is 
 not available anymore.

 I am using Pacemaker/corosync with two virtual IPs (service IPs exposed 
 to the clients), so each node has its corresponding virtual IP, and if 
 one node fails, corosync assigns the failing IP to the other running 
 node). This mechanism works pretty good so far.

 So, I have:

   gluster1: IP 10.196.150.251 and virtual IP 10.196.150.250
   gluster2: IP 10.196.150.252 and virtual IP 10.196.150.254

 Now I am using DNS round-robin to distribute the load on both gluster 
 nodes (name: gluster.mycompany.tld).

 If one node goes down, the virtual IP is handed over to the remaining 
 node, and the client works without any disruption. However, if the 
 replication link between the gluster nodes breaks, we examined a service 
 disruption. The client was then unable to write data to the cluster. The 
 replication links between gluster nodes seems to be a single point of 
 failure. Is that correct?

 Daniel