Longhorn supports iSCSI target frontend mode. The user can connect to it through any iSCSI client, including open-iscsi, and virtual machine hypervisor like KVM, as long as it’s in the same network with the Longhorn system.

The Longhorn CSI driver doesn’t support iSCSI mode.

To start volume with iSCSI target frontend mode, select iSCSI as the frontend when creating the volume. After volume has been attached, the user will see something like following in the endpoint field:

iscsi://10.42.0.21:3260/iqn.2014-09.com.rancher:testvolume/1

Here:

1. The IP and port is 10.42.0.21:3260.
2. The target name is iqn.2014-09.com.rancher:testvolume. testvolume is the name of the volume.
3. The LUN number is 1. Longhorn always uses LUN 1.

Then user can use above information to connect to the iSCSI target provided by Longhorn using an iSCSI client.