High availability for ceph storage?

Solution 1:

You need at least 3 MON to achieve HA because of the quorum. With only 2 nodes your storage will be stopped by an problem on one node.

"When a Ceph Storage Cluster runs multiple Ceph Monitors for high availability, Ceph Monitors use Paxos to establish consensus about the master cluster map. A consensus requires a majority of monitors running to establish a quorum for consensus about the cluster map (e.g., 1; 2 out of 3; 3 out of 5; 4 out of 6; etc.)." link

If you need HA storage with 2 nodes take a look at solutions which has been designed for this. I can recommend StarWind VSAN free with active-active replication and no quorum requirement.