View Full Version : Multiple two node clusters within 4 nodes

08-May-2019, 06:00

the need is to manage multiple 2 node clusters from single node with crmsh

Tried the following cluster configurations steps:

1. Create a 4 node cluster - node1, node2, node3, node4
2. Changed the corosync.conf on node1 and node2 to specify node list as node1 and node2 with expected_votes: 2 and two_node: 1
3. Changed the corosync.conf on node3 and node4 to specify node list as node3 and node4 with expected_votes: 2 and two_node: 1
4. Created 2 sbd from same device partitions - stonith-sbd1 and stonith-sbd2
5. stonith-sbd1 for node1 & node2
6. stonith-sbd12for node3 & node4
7. also added constraints for resources including stonith to run on only 2 nodes (within each 2 node cluster)

8. tested the cluster for n/w partitions and failovers and it worked fine.

Is this a valid supported configuration?


09-May-2019, 17:56
I've dealt with a lot of clusters and never seen anyone use such a configuration. Most users run multiple two node clusters, or as a normally configured cluster with resource constraints. Other than not running commands specific to two clusters I don't see much benefit here, just concerns on what behavior it may cause.
Would not recommend this configuration as its not designed to be used in such a way. Support would be best effort depending on where an issue occurred and may result in a recommendation to split it into two clusters.

Can you elaborate on what the need to control all four nodes from a single node is? Might be a simpler way to reach your goal.

10-May-2019, 05:05
The requirement is similar to Hawk UI functions in CLI form. Want to use crm for automation scripts to manage multiple clusters.
I hit this configuration accidentally while trying out few things:-)