Most iSCSI targets involve disk, though iSCSI tape and medium-changer targets are popular as well. So far, physical devices have not featured native iSCSI interfaces on a component level. Instead, devices with Parallel SCSI or Fibre Channel interfaces are bridged by using iSCSI target software, external bridges, or controllers internal to the device enclosure.
Alternatively, it is possible to virtualize disk and tape targets. Rather than representing an actual physical device, an emulated virtual device is presented. The underlying implementation can deviate drastically from the presented target as is done with virtual tape library (VTL) products. VTLs use disk storage for storing data written to virtual tapes. As with actual physical devices, virtual targets are presented by using iSCSI target software, external bridges, or controllers internal to the device enclosure.
In the security products industry, some manufacturers use an iSCSI RAID as a target, with the initiator being either an IP-enabled encoder or camera.
July 26, 2011