The EN104L+ can act as both an iSCSI initiator (it can connect to iSCSI target volumes) and have some of its storage partioned off into iSCSI targets. The Initiator controls are shown in Figure 5 and include the essentials of target discovery and log in / out.
Figure 5: iSCSI Initiator settings
Creating an iSCSI target is done in the Logical Volume Manager. All you do is select the physical volume (there's only one), fill in the Volume Name, select iSCSI as the Volume Filesystem (the other choices of XFS and ReiserFS are used for SMB/CIFS, AFP and NFS accessible volumes), optionally enter a Volume Description, enter the Volume Size and click the Create button. Volume creation was virtually instantaneous.
Figure 6: iSCSI Target creation
I didn't have much luck with the EN104L+' backup features under its Replication menu. I tried using a Synology DS109+ as an rsync target (Figure 7), as I had with other NASes. But although it appeared that the EN104L+ could find the Synology target, it wouldn't accept the password. If I had been able to schedule a replication, note that I could have run it as often as hourly!
Updated 9/3/2009: Sans Digital said that backup / replication to generic rsync targets is not supported.
Figure 7: Folder Replication
I then was going to try using an attached USB drive as the replication target. But each time I tried to assign a device name, I got the "Error. 5" shown in Figure 8.
Figure 8: USB volume add fail
The other "backup" option provided is volume "snapshot" (Figure 9). This isn't really backup, since it is stored on the same physical device. But a snapshot can provide some protection against accidently deleted and corrupted files. You can schedule snapshots once daily, weekly or monthly.
Figure 9: Snapshot screen
Each snapshot is actually another volume that inherits the access controls of its parent volume. You need to set the size of the snapshot volume, however; it's not set automatically. I didn't try testing the snapshot feature since I had struck out on getting the Replication features to work.
Finally, note that Sans Digital doesn't bundle in any backup programs for Windows or any other OS, for that matter. In all, I wasn't impressed with the EN104L+' ability to back itself up.