https://www.ibm.com/docs/en/flashsystem-5x00/8.4.x?topic=details-hyperswap-system-configuration

First set site for all components:

• chsite : define 3 sites
• chnodecanister : assign canisters
• chcontroller : assign controlers and quorum
• chhost : assign hosts to each site

Few things you need to keep in mind:

1. When switching to HyperSwap, you will need to "delete" one of the systems, as it's nodes need to be in candidate state and to be visible from the master cluster. 
* Therefore in this case, in order for this to be a non-disruptive process, provided at the moment both systems have data on them, you will need to migrate the data from one of the systems on to the other. 
* Furthermore, it's highly recommended that both systems are identical in Hardware and Storage, so that one does not underperform or fill it's capacity before the other. (Same system, with the same amount of RAM, same HIC adapters and same storage capacity) 
* Once the migration of data and hosts is done, and the second system is prepared to be added to the first, you need to run **leavecluster -force** on both it's nodes, which will make them candidate. 

chsystem -topology hyperswap

2. When the HyperSwap cluster is established, you need to keep a couple of things in mind. 
* Due to the nature of HyperSwap, a single volume will have 4 copies. Master and Aux on the master site, Master change and Aux change on the Auxiliary site. This means that for each volume you will need more resource (bitmap memory) and more objects will be taken (4 per volumes, instead of 1, in normal topology clusters). 
* When the above is agreed and the HyperSwap is established, you can start making the existing volumes HyperSwap volumes, which is done via the link I sent in my initial post -> Right click on the vdisk -> Add Vdisk copy and then follow the procedure in the GUI. 
* Once this is done and the data is migrated, you will have a fully fledged HyperSwap cluster. Also make sure that all volumes are hyperswapped, as otherwise, the purpose of this topology is a bit lost. Hosts need to have access to both "sites" and equal paths to both I/O groups, in order to operate properly, in case one of the systems undergoes maintenance or encounters an issue.