[ClusterLabs] Automatic recover from split brain ?

[Adam Cécile]

Hello,


I'm experiencing issue with corosync/pacemaker running on Debian Buster. 
Cluster has three nodes running in VMWare virtual machine and the 
cluster fails when VEEAM backups the virtual machine (I know it's doing 
bad things, like freezing completely the VM for a few minutes to make 
disk snapshot).

My biggest issue is that once the backup has been completed, the cluster 
stays in split brain state, and I'd like it to heal itself. Here current 
status:


One node is isolated:

Stack: corosync
Current DC: host2.domain.com (version 2.0.1-9e909a5bdd) - partition 
WITHOUT quorum
Last updated: Sat Aug  8 11:59:46 2020
Last change: Fri Jul 24 07:18:12 2020 by root via cibadmin on 
host1.domain.com

3 nodes configured
6 resources configured

Online: [ host2.domain.com ]
OFFLINE: [ host3.domain.com host1.domain.com ]


Two others are seeing each others:

Stack: corosync
Current DC: host3.domain.com (version 2.0.1-9e909a5bdd) - partition with 
quorum
Last updated: Sat Aug  8 12:07:56 2020
Last change: Fri Jul 24 07:18:12 2020 by root via cibadmin on 
host1.domain.com

3 nodes configured
6 resources configured

Online: [ host3.domain.com host1.domain.com ]
OFFLINE: [ host2.domain.com ]


The problem is that one of the resources is a floating IP address which 
is currently assigned to two different hosts...


Can you help me configuring the cluster correctly so this cannot occurs ?


Thanks in advance,

Adam.