Edit (adding users , so that they can correct me if im wrong , or provide more inputs)
Hi Holger,
Yes, (someone else correct me if im wrong), it is possible via gluster ansible deployment, and if i'm not wrong , initially you need to deploy the usual 3 node setup and then add then add in further hosts in the sets of 3 ( i believe maximum of 12 nodes is supported) and then create a new gluster volume in the new nodes and then expand the existing nodes to accommodate new disks on the new host.
i believe this
doc should you give you a little insight:- its a little old but gives you an idea
hope this helps!
Regards,
Prajith Kesava Prasad.