May 21, 2012, 9:51 AM — Many technologies originally intended for the enterprise end up trickling down into the consumer market at some point. Some of these technologies (ethernet or virtualization, for instance) are more practical than others; but if businesses find a use for a specific piece of technology, then chances are good that consumers can benefit from it as well. Such is the case with iSCSI.
iSCSI stands for Internet Small Computer System Interface. SCSI (sans i) has long served to connect a variety of peripherals to computer systems, but most commonly it appears in storage devices, such as hard drives or tape-backup drives. iSCSI builds upon the base technology by allowing users to connect to a remote storage volume over a network, as if said storage volume were a locally attached disk. Simply put, iSCSI transmits SCSI commands over IP (Internet Protocol) networks. iSCSI is like a virtual SATA (or SCSI) cable, in that it uses a network connection to link a system and a storage volume.
Judging from that description, you may be wondering how iSCSI differs from any other network share with a mapped drive letter. On many levels, the end results are similar. With iSCSI, though, the attached volume appears to the operating system as a locally attached, block storage device that you can format with the file system of your choice. In addition, fewer layers of abstraction separate an iSCSI volume and your PC, which can result in increased performance.
Ready to get your hands dirty with some hardware? If you wish to use iSCSI, there are two main requirements: a network-attached storage device or server with a volume that can be configured as an iSCSI target, and an iSCSI initiator, which allows a system to connect to the target.
If you own a NAS drive attached to a Windows PC (or if you have managed to make your own NAS), you probably have everything you need; virtually all NAS (network-attached storage) servers offer the ability to configure iSCSI targets, and Microsoft has included an iSCSI initiator tool with every version of Windows since Vista. You can download and install Microsoft's iSCSI initiator on all previous versions of Windows from 2000 on up, too.