What is the default role for DRBD nodes

I have upgraded a node in a two-node DRBD cluster as follows: 1. reinstall Debian 2. apt-get install drbd-utils 3. systemctl start drbd 4. obtain /etc/drbd.d/my_resource.res from backup 5. configure block device (disk) and IP address for DRBD resource 6. systemctl reload drbd At this point DRBD starts to resync and the cluster becomes operational again. My question is this: what determines if the node acts as DRBD primary or secondary at this point. In my case the opposite node was the primary, so it was important that the upgraded node started as secondary. Is this the default?