DRBD: Wrong medium type while trying to determine filesystem size

If you encounter the following error when trying to format a DRBD device:

mke2fs 1.41.12 (17-May-2010)  

mkfs.ext4: Wrong medium type while trying to determine filesystem size

The node you are executing the command on is configured as Secondary instead of Primary, verify this by running the following command:

drbdadm role <resource>

If you see:

Secondary/Primary

It means that the node you ran the command on is Secondary, to fix it run the following command on the current node(primary):

drbdadm primary <resource>