[ovirt-users] Changing of master storage domain

Hello there, I have a question about the algorithm of changing of master storage domain. I have a fresh installation of oVirt 3.6 on 2 hardware nodes, using a number of NFS shares as storage domains, and one of them was a master. When I was adding the second node into cluster, master storage domain had been changed by oVirt. Actually it didn't bring any harmful consequences at that point but it was unexpected for me. So, could anybody please explain such behavior of oVirt and also explain whether I could change master storage domain back to the previous? -- Thanks in advance, Roman Chukov.