Configuring site information for the system

Using the management GUI

You can use the Modify System Topology wizard in the management GUI to easily configure the site names and assign objects on your system to a site. The Modify Topology wizard automatically detects any Fibre-Channel-attached storage, but iSCSI storage must be added manually before the site assignments can be configured. You can use either the management GUI or the command-line interface to add Storwize systems. Dell EqualLogfic systems can be configured with the command-line interface only. Complete the following steps to configure the topology for the system and to optionally add iSCSI-attached storage:

In the management GUI, select Monitoring > System. In the System Actions menu, select Modify System Topology.
Follow the wizard to complete the configuration of the HyperSwap® topology.
If you are using iSCSI-attached external storage, you must add the storage to the system and specify the site by using the Add iSCSI External Storage wizard. To access the wizard, select Pools > External Storage > Add iSCSI External Storage.
Select the type of external storage system that you are adding.
Enter the information for the source and target ports for the iSCSI connection and specify the site for the iSCSI-attached storage.

Using the CLI

You can also use the command-line interface to configure site information and configure the system as a HyperSwap topology. Separate commands are used for each configuring site definitions for the necessary objects on the system. Although you do not need to name sites, creating names that are based on the location or use of the site simplifies management of the HyperSwap topology. Complete the following steps to configure site information and set the system as a HyperSwap topology:

For easier management of the HyperSwap topology, create specific names for each site on the system. If names are not specified, sites can be referred to by their default name or numeric ID. Enter the following command to create specific names for each site.
```
chsite -name losangeles 1
```
In this example, site 1 is now named losangeles. To rename the other sites in the HyperSwap topology, enter the same command with names for the other sites:
```
chsite -name sandiego 2
chsite -name quorum 3
```
In this example, site 2 is now named sandiego and site 3 is named quorum.

Note: IP quorum applications can be used at a third site to provide a tie-break if connectivity is lost between site 1 and site 2. For more information, see the IP quorum configuration information.
Enter the following command to assign existing external storage systems to sites:
```
chcontroller –site losangeles storagesystem1
```
In this example, storagesystem1 is assigned to site losangeles. To assign a storage system to the other site, enter the following command:
```
chcontroller –site sandiego storagesystem2
```
In this example, storagesystem2 is assigned to site sandiego.
If you plan to use an external storage system to provide quorum, then you must assign that to the third site. Alternatively, an IP quorum application can be used to provide quorum. For more information, see the IP quorum configuration information. To assign an external storage system to the third site, enter the following command:
```
chcontroller –site quorum storagesystem3
```
In this example, storagesystem3 is assigned to site quorum.
You must assign a site for all storage systems that are present in the configuration.
Enter the following command to assign existing hosts to sites:
```
chhost -site losangeles host1
```
In this example, host1 is assigned to site losangeles. If you have other hosts, you can assign them to other sites:
```
chhost -site sandiego host2
```
In this example, host2 is assigned to site sandiego.
Note: If you configure your system so that a host is connected only to nodes in a single site, consider changing the statussite policy to local (statussite local) so that the host is not reported as degraded.
```
chsystem -topology hyperswap
```
Optionally, configure bandwidth settings for the background copy operations between each site by entering the following command:
```
chpartnership -linkbandwidthmbits 2048 -backgroundcopyrate 50 mysystem
```
Background copy is the term that is used for the initial synchronization and any subsequent resynchronization traffic for HyperSwap volumes in the system.

After you complete these steps, you can configure HyperSwap volumes to create copies at each site.

Configuring an external iSCSI controller by using the CLI

After you change the system topology to hyperswap and nodes are assigned sites, you can configure an external iSCSI storage system by completing the following steps.

From the nodes of site 1, discover the iSCSI target storage system:
```
detectiscsistorageportcandidate –srcportid 1
 -targetip IP1 -site 1 
```

Check the status of the discovered targets:

lsiscsistorageportcandidate id src_port_id target_ipv4 | target_ipv6
 target_iscsiname iogroup_list configured status
 site_id site_name 0 1 IP1 IQN1 1:1:1:1 no Full 1 site1

From the nodes of site 1, add a session to the discovered targets:
```
addiscsitorageport -site 1 0
```

From the nodes of site 1, view the established sessions with the target:

id src_port_id target_ipv4 | target_ipv6 target_iscsiname
 controller_id iogroup_list status site_id site_name
 0 3 IP1 IQN1 5 1:1:1:1 full 1 site1

The new storage system can be shown as available by entering the lscontroller command. Assign a site:
```
chcontroller -site 1 controllerID
```
From the system nodes of site 2, repeat steps 1 through 5 for discovering and establishing sessions to the same iSCSI controller or a different iSCSI controller.