Troubleshooting

Run the below command on the master node:

            

            
/etc/init.d/ufmd status  
        

Run the below command:

            

            
ufm_ha_cluster status 
pcs status 
        

Run the below command:

            

            
ufm_ha_cluster status 
        

Run the below command:

            

            
drbdadm sh-resources 
        

Run the below command:

            

            
drbdadm dstate ha_data 
        

Run the below command:

            

            
drbdadm role ha_data 
        

Run the below command:

            

            
drbdadm cstate ha_data 
        

Step 1:

Manually choose a node which data modifications will be discarded.

It is called the split-brain victim. Choose wisely; all modifications will be lost! When in doubt, run a backup of the victim’s data before you continue.

When running a Pacemaker cluster, you can enable maintenance mode. If the split-brain victim is in the Primary role, bring down all applications using this resource. Now switch the victim to the Secondary role:

            

            
victim# drbdadm secondary ha_data 
        

Step 2

Disconnect the resource if it’s in connection state WFConnection:

            

            
victim# drbdadm disconnect ha_data 
        

Step 3

Force discard of all modifications on the split-brain victim:

            

            
victim# drbdadm -- --discard-my-data connect resource 
        

For DRBD 8.4.x:

            

            
victim# drbdadm connect --discard-my-data resource 
        

Step 4

Resync starts automatically if the survivor is in a WFConnection network state. If the split-brain survivor is still in a Standalone connection state, reconnect it:

            

            
survivor# drbdadm connect resource 
        

Now the resynchronization from the survivor (SyncSource) to the victim (SyncTarget) starts immediately. There is no full sync initiated, but all modifications on the victim will be overwritten by the survivor’s data, and modifications on the survivor will be applied to the victim.