Changing the system topology

You can use the command-line interface or the management GUI to change the system topology.

About this task

The system supports three system topologies. In a standard topology, the system is configured on a single site. Both the HyperSwap® and stretched system topologies are configured among multiple sites and are used for high availability and disaster recovery solutions. With the HyperSwap topology, I/O groups are configured at each site and require a license to the Remote Mirroring function. The stretched system topology splits the I/O group among each site, where each node in the I/O group is associated with a separate site. You can change the system topology from HyperSwap or stretched to a standard topology, but cannot directly change the system topology from HyperSwap to stretched, or vice versa. HyperSwap volumes must be removed or converted to basic volumes by deleting a copy before changing the topology, but stretched volumes do not need to be removed or changed in anyway.

Use the -topology parameter in chsystem command to change the topology of the system. In the management GUI, select Monitoring > System. In the Actions menu, select Modify System Topology.

Procedure

To change the system topology from either a HyperSwap or stretched system to a standard topology, enter the following command:
```
chsystem -topology standard
```
To verify that the site definitions have been removed from the node, enter this command:
```
lsnode
```
If either the site_id or site_name parameters are listed, remove the site definitions from the node by using the chnode command.