Internet Small Computer Systems Interface, which stands for iSCSI, is based on Internet Protocol, which allows the transmission of SCSI commands over a standard IP-based network. iSCSI devices can be set up locally or over a vast distance to provide storage options. We cannot store virtual disk images directly on an iSCSI device, but we can configure LVM storage on top of the iSCSI devices and then store disk images. An attached iSCSI device appears as if it were physically connected even if the device is stored in another remote node.

For more details on iSCSI, refer to the following link:

http://en.wikipedia.org/wiki/ISCSI

We will assume that you already have an iSCSI device created in a remote node using FreeNAS or any other Linux distribution. To add the device to Proxmox, we are going to use the iSCSI storage plugin, which we can find by navigating to the Datacenter | Storage | Add menu. As shown in the following screenshot, we are adding an iSCSI target named test1-iSCSI, which is configured in a remote node, 172.16.2.10:

Note that using LUNs directly is not recommended, although the option to enable them is available. It is known to cause an iSCSI device error when accessed directly.