Hello Sven,   Sorry no.  There's no "merge" group capability.  Plus the Discovery addresses are different so the servers have to be updated.   If you have enough space you can migrate data to one group.  I.e. via Storage vMotion for VMware, then reset the freed member and add it to the group.    Any solution you are looking for will be host based.   Regards, 
Hi everybody, Is it possible to add an existing PS6110 with existing volumes and iSCSI connections to an existing group without interruption? Thanks! Sven
Add PS6110 with existing data to existing group